Basically, we come up with (legal) combinations of Flaws that necessarily work out to weird characters. Part of the fun of this game is that the we're judging the parts of the character by how the Flaws shape them; obviously a Blind archer is weird, but there isn't a "required to be an archer" Flaw, so that isn't shaped by the Flaws and is thus disqualified from the game.
So far, my favorite is one that uses all of your Flaw points on Hermetic Flaws, namely Rigid Magic, Unstructured Caster, Weak Spontaneous Magic, and Difficult Spontaneous Magic. If there was a cheaper way to remove all casting, I'd also throw on Weak Enchanter or something akin to it, but as it is, this gives you a magus who can't actually cast any spells. (Except maybe rotes.) That's as close as I've gotten to making a magus who can't work magic, which is pretty self-contradictory to say the least.
Err, I don't. I mean submitting a combination of flaws for a Hermetic magus who can't cast any magic, is nearly the blind archer.
But a Diedne Magic character with Chaotic Magic is still a bit of an odd duck, and not even close to being in the same area as either option in the OP.
I've played a character with Unstuctured Caster and Rigid Magic. Putting on the inability to work spontaneous magic would be a bit too far.
Perhaps these should be characters that have seen some play.
Curse of Venus + Optimistic (major) + Monastic Vows (Hermetic)?
(Had to be the Hermetic version since the non-Hermetic version would make two Story Flaws.) People keep falling (in love, lust, whatever) for you and trying to get you. You can't be with them, but of course they clearly only have the best of intentions so everything will turn out OK.
Sounds like a slightly more difficult version of the Verditius I'm currently playing. Painful magic means that while he CAN cast spells, he sure doesn't want to. He just spent an entire season making a magic item for a spell he can spont.