1) Did you actually try pushing it in slow and starting the car and it didn't work? or did you just listen to what he said and kicked the clutch?
2) By "unable to get it in" do you mean that it was just taking a bit too much force for your taste? If this is the case, the trick I learned from my trusty mechanic is, while still applying pressure into the right/down direction, let the clutch out just a little bit. It should then slip right in.
3) That's the difference between a shifter and a !Removed!: the softer the shift, the better. (Yes I said !Removed!)
Sounds like a decent deal.
Ask if the waterpump, timing belt, etc have been replaced.
If not, tell him they should have been and offer $6500
Make sure you plan on keeping this car for a while because you might have trouble reselling it for a decent price (because of the salvage title)
Otherwise it sounds like a decent deal to me.
Good luck.