Summer 1209 is when apprenticeship is finished so that should be included in character generation xp.
Autumn 1209 is adventuring which could be put in any physical abilities and maybe some arts that I'm likely to use Muto, Animal and Imaginem comes to my mind.
Winter 1209 is covered for at Oculus.
Spring 1209 is the trip from Lübeck to Anvers. Do I get anything other than Exposure, and exposure to what Swimming and Area Lore perhaps?
Autumn - I'll be generous and give you a generic 10 xp. 
Winter - I rolled to see how courteous Oculus felt towards you. Did fairly good, so you got access to a nice Q11 summa.
Spring - Sounds right, exposure xp only. Note that the actual travelling to Anvers doesn't take the whole season, so you may allocate exposure to some other ability that makes sense to his activities.
Hallelujah! 
I put 2 xp each in Awareness, Heartbeast, Stealth, Survival and Muto.
Who doesn't like a dolphin?
It sounds a bit selfish to just study it and not copying it but I guess this was before Bernhard showed up and he probably wasn't allowed to copy it either by Oculus.
You were indeed only given study access to the summa, so the point is moot.
Here is a first shot at the stats for the magical otter.
Fischer, the magical otter
Characteristics: Int 0, Per +1, Pre -2, Com 0, Str -5, Sta +1, Dex +3, Qik +5
Size: -3
Magic Might: 6
Virtues & Flaws: Magic Animal, Puissant Swim, Carefree
Qualities: Amphibious, Hardy, Keen Sense of Smell, Pursuit Predator, Tough Fur
Abilities: Awareness 3 (underwater), Hunt 4 (fish), Swim 4+2 (speed), Survival 5 (aquatic environments)
Magical Qualities: Focus Power, Gift of Speech, Improved Soak, Personal Power
Powers: Crafter of Aquam, Hands of the Magical Animal
Looks fine to me. I assume you'll add some additional virtues/powers/etc to personalize your companion?
I might add a Virtue but I took Magic Qualities and Powers for the worth of Might 6.
I will add some personality traits.
I'm also not sure exactly how Crafty with Aquam works. He can cast Creo and Rego Aquam spells up to 25 spell levels and also limited by Might. Do I choose these spells beforehand or can they be cast spontaneously so to speak?
From what I understand, it works as spontaneous magic. He can create effects of a level up to his Might, for the cost of 1 Might Point per magnitude.
So these would be low-level CrAq and ReAq effects.
You'd need to give him a Might of 10 in order to be able to perform 2nd-magnitude effects. The choice is yours.
I think Intelligence 0 is a bit high according to the guidelines on a magical animal companion. At Size -3 it shouldn't be as intelligent as an average human.
Regarding Crafter of Aquam, it basically let you mimic spontaneous magic, but for a narrow range of effects. Crafter of Aquam, for instance, let you manipulate the form of Aquam, although I'm not sure if it should read that you can use it to spont CrAq and ReAq effects, or if you have to choose between the two when you take it, or if you must specify a 'specific range of Non-Ritual spells'. All possible CrAq and ReAq effects seem a bit too large (and why would your otter create beer, or ward against water faeries ?) but if you restricted it to water (creating it and manipulating it) it would be just about perfect.
In any case, you are limited by the Might of the creature, which isn't much... unless you take the Improved Powers minor magical quality, which would allow you to raise the maximum by up to 25 levels (to 31 in theory, although the limit of 25 for the Focus Power applies). The cost of 1 Might per magnitude stands, however, so your otter would be able to do one really good effect per day. You could take the minor inferiority Susceptible to Deprivation to pay for it.
Alternatively, you can restrict your Focus Power to a lower level (for instance 15) and convert the 10 missing levels into two mastery points which you immediately use to raise your Might limit by 10 levels (to 16) : that will allow you to do up to level 15 effects, without taking another quality.
lol. So much for restricting ourselves to the core book and GotF as the available books for charGen 
Regarding Crafter of Form, it has always had this "create beer" (otter) or "manipulate cold" (salamander) or "Rise the dead" (corpus healer bird) problem. If you use the power in an anti-characterful way you can always break it. IMO the easy thing is not to do that and then you do not have a problem 
Cheers,
Xavi
I guess the key question is how much influence we, the troupe, want this otter to have in our saga. I took this story flaw since I didn't have any and I had a minor flaw slot left. Then it was Animal Companion or Magical Animal Companion that fitted my character best.
If someone wants to and if Arthur approves of course he could be made as a Companion character maybe? With the Human Shape power and Gift of Speech he can interact pretty much as normal. We could also change the whole otter concept making it a different animal but preferably with aquatic or amphibic preferences. Just a thought.
If not played I guess he should take a lesser role in the saga. Maybe his stats and powers are not as important to define in detail. He can speak and he can do some minor stuff with water, making beer is quite fun for an otter. Especially if he has the Hands of the Magical Animal, then he can serve it in mugs as well. His main role in the saga then will be to trigger stories when he get in trouble.
Well, I for one have no particular interest in playing an otter as a companion. But I have no problem if someone else wants to.
I have no problem if this becomes a companion-level character, but if that is the case, then another player needs to take charge of him.
We haven't discussed the possibility of introducing companions to the saga until now, but in general I find that in a PbP saga, where parallel threads are easier to handle than with a face-to-face game, companions are often see little play. They end up being just a bunch of stats providing the covenant with something it values.
So unless someone presents the troupe with a strong concept that integrates well into the saga, I don't think we will use companions.
Indeed, his stats aren't much of an issue. So a good description of his origin and essential nature (very important for a magical creature as it is essentially unchanging) are more important to me than stats. He should be there to provide color in the saga. And story hooks, of course.
The only evolution to the character would be if Japik decides to make him into his familiar. If that happens, we can pick another flaw to fill that spot. I'm sure something appropriate will come up after some time spent playing him. 
In RAW Bjornaer magi can't bind familiars so this would be as close as he gets. Unless you house rule otherwise of course.
I will write something up for him. I see him as an even bigger prankster than Japik so he is likely to get into trouble. Since he was born at or near a Creo vis source that should also be reflected in his essential nature.
I forgot that Japik was a Bjornaer. 
And it is unlikely that another magus will try bind your companion to himself, as this would take him away from you. Although that might make an interesting story, should a foreign magus try to claim him. 
Indeed it is. Especially if the magus comes from Waddenzee... 
The future familiar has to willing to be bound. It can't just be forced upon it.
Of course, a bag full of plump trouts might tempt the otter away
Don't give him ideas!!!!
I know, but I think he already had them in this case.
I like the dolphin stats. I'll use them. Thank you!