I play both ice and inline year 'round. Ice on Wednesday, Friday, and Sunday. Inline on Monday.
I agree with elite, in that inline will help somewhat with your games on ice. Angles and reactions (on side to side plays and wraparounds) are more critical in inline games, as well as the conditioning benefits that have been mentioned.
However, you must be aware that breakaways can be tricky. On ice the player often has the advantage and can make more plays and change direction quicker. Inline goalies often have the advantage because only a very few players can change direction that quickly, and most of them can't or fall trying.
The funny thing is that in the 2 or 3 years I have been playing both, I have picked up several things from my inline games that really help with my ice games. Not much from ice really helps my inline play, but hasn't hurt it either.
The only real dissadvantage for me is having to switch my leg pads, skates, and such between my ice and inline games. As well as I play with a different stick because I am a little higher off the floor in my inline skates.
I've never had any real difficulties with my movements like you mentioned because of switching back and forth, if I have I guess they clear up during warm-up
