if i were you, i'd make sure i could access the data on the faulty HDD first.
if i can access the data, and if sector by sector copy isn't possible, i'll start saving anything i can't make do without.
then just clean install on the new HDD.
now to really answer your question:
2a. yeah, you should be able to. if you couldn't, use a desktop pc to perform the data recovery. (get converter dongle)
3a. do it, and try to fix problems that may come along the way.
no siggy, saw stuff that made me sad.