I have this idea of a mage who never leaves his lab and uses Grogs to explore the world.
He would place an arcane link on some grogs and would be able to see what they do with InIm and talke to them with CrMe. Maybe even control them when needed with ReMe.
He could even cast spells though a ReVi Tunnel.
My problem is that it seems too easy to do. Is'nt there some limits on what a mage can do remotely ?
For starters, you'd need Arcane Connections to everything you want to affect. +4 magnitudes in all of your spells seems like a good limit. You can bypass this with Intangible Tunnel, sure, but this still isn't perfect.
A Tunnel to anything would allow you to target that thing only. You can't target a Room spell in the room the end of the Tunnel is (unless the room itself is the target of the Tunnel), you can't target someone else close to your target.
You can equip your grogs with several enchanted items, sure, but they can't improvise a spell if eeded (and it is going to be). Also, remember that you have Parma. Your grogs don't. You are (usually) safer from any kind of mystical effects.
You lose A LOT of flexibility.
And sometimes there will be an enemy capable of sensing the Tunnel and targeting you back through it. This would be rare, of course, but then, things that seriously and directly affect most magi are rare to begin with (well, if the magi is doing his best to keep safe at least).
This all said, I think it's a neat concept. I can see several ways in which things could go wrong and the magus being forced to take the lead sometimes (just to spice things up), but I don't thing there is anything wrong with him solving things at distance either (what is the difference between this and a magus who can use ReCo to teleport back to his sanctum and go back to the grogs only if required?).
No, there is no limit to what the magus can learn to do eventually. There is, however, a limit to what he can actually do at present.
As @RafaelB says, you are talking about high magnitude spells, and not just one spell, but a range of spells across many different arts. It will take decades to develop them all, and then some effort to figure out how to use them effectively. I suggest you make the saga about developing and field testing the spells one by one. When the magus is actually able to adventure fully by proxy, it may be time to start a new story about something else.
There's a character in a saga I play in that uses something similar (controlling magically animated bodies instead of living grogs, but very similar).
Having to do everything at arcane connection range and through intangible tunnels is a big hurdle that's already been mentioned.
The issue of what happens if events at the magus' real location distract them at a crucial moment. Suddenly the puppets are left without guidance and have no idea why, and no means to do anything about it but wait for the magus to (hopefully) sort out the problem.
This is purely optional, but we house ruled that the magus' presence could be felt even though they aren't physically present. The Gift becomes a -1 penalty and the Blatant Gift a -3, which effects people interacting with whatever thing(s) the magus is puppeteering. This makes it a bit less OP in social scenarios while still providing a benefit for the magus.
How willing are the grogs? It's kind of creepy and if they aren't entirely on board with it then usurping their free will regularly may lead to a collapse of morale.
How much are the effects being used, and how powerful are they? Warping can become a serious issue here - even a fairly moderate spell can push into "strong mystical effect" territory if you make it arcane connection range.
It's bound to have some weird effects on the magus' psyche. Spending so much time in someone else's senses can't be good for you, right?
Depending on the nature of the regio and your saga's interpretation, your control may break down when the puppets enter regiones. This is also an issue if they enter an Aegis. Or Arcadia.
Those sorts of spells look awfully suspicious. Other magi may begin to suspect unsavoury things about your character (even if it's completely untrue). Some may consider it to be uncomfortably close to scrying on them if you use it nearby. At the very least, it gives you the ability to spy on them via their grogs if you gain an arcane connection.
Your mileage may vary, but all I can say is we've had fun with it in our saga and there are more (interesting) problems with the idea than you might think at first glance.
I don't think a concept like that would care much of his reputation or his grogs morale.
But the Scrying part would indeed be an issue.
I'll try to see if there is a way to create a fun mentem character with possible evolution toward this wicked concept
I have an NPC that works like this in my current saga. She's ancient, decrepit, paranoid, doesn't want to leave her sanctum, and hates people. So she has a few beggars who do what she asks because she can temporarily alleviate their pains, and when she wants to "go out" she Creos a fake (Moon) human body, animates it as an undead (Moon duration), hacks off a finger, dresses it like a lepper, gives it a bell to ring as it walks, and tells it "follow this beggar". Then (usually at set times) she uses Arcane range spells to see, hear and speak through the body (she still can't move it). That way she can check in with it, and if needed give more instructions to the beggar. This gives her a really limited ability to see what is happening wherever her beggar is going, and to negotiate "in person" without having to leave her lab. It isn't of great use to her, but it creeps the players out and it's the sort of thing you probably think is normal when your a 100-year-old reclusive Criamon necromancer