[Lethe]

In fact I understand channeling according to skills as the possibility to have a spirit allowing you the use of a skill you don't have (or you want to boost a bit) like a skillsoft.

Well, nowhere in channeling it states, you can use the spirits skills, so that's definitely wrong. You can order the spirit to use his skills, but he can't use the aid on himself then.

For the drain, as I said previously, if you have another ally he can resist the drain at your place so, not a big issue (if you want a bad rep with your spirits of course) 

If you are that mean to your spirits, be prepared that all further spirits will use edge to resist your summoning, which in this case will cause an average 32P drain damage and will definitely make you fail that binding. Its not getting prettier.

[blackangel]

In fact I understand channeling according to skills as the possibility to have a spirit allowing you the use of a skill you don't have (or you want to boost a bit) like a skillsoft.

Well, nowhere in channeling it states, you can use the spirits skills, so that's definitely wrong. You can order the spirit to use his skills, but he can't use the aid on himself then.

I can easily imagine a way to bypass this problem for magical skills and keeping the aid sorcery

For the drain, as I said previously, if you have another ally he can resist the drain at your place so, not a big issue (if you want a bad rep with your spirits of course) 

If you are that mean to your spirits, be prepared that all further spirits will use edge to resist your summoning, which in this case will cause an average 32P drain damage and will definitely make you fail that binding. Its not getting prettier.

I can easily imagine one or two ways to bypass this one (if you assume that you don't use the dice pool limitation)

But in fact it's only theorically except if your players want a kind of superheroes game 

Out of theory I'm thinking to put a limitation to the level of the skill a player can use threw a spirit as for the attributes. Meaning a max of 6 or 7 depending on the aptitude adavantage.