You're good to go. IIRC your brake cables might be a bit short, but I only half-remember that.
As for being caught out by derailers, with Shimano all you need to know is that MTB FDs are different to road FDs (I think there are flat-bar shifters for road FDs), and 10s MTB (Dynasys) and 8s DA (RD-7400) RDs are oddballs. (The RD-7400 will shift 8s with a 9s shifter.)
I think that's about it, except the RDs from groups featuring the new-style aero STIs seem to have a slightly different actuation ratio that seems very similar overall, but means if you replace it with an earlier RD, it'll shift like absolute crap. Presumably vice versa too, although the overall ratio is probably similar enough for one of the recent RDs to shift 7s or 8s okay.
I was warned by a colleague and my scepticism made me go ahead and suck it to see, and boy, did it suck. The whole situation sucks; he said he saw it in a PDF somewhere, but no-one else seems to know about it and I haven't seen anything about it online... I'd have said he's tripping - in fact I did, until I saw it myself. We had no choice but to order the proper derailer, then Bob's yer uncle.