You need to.....

So if you were starting again with a clean blank slate, what would you say are the vital things to do to your f/tf?

Make it completely rust free, dent free, and perfect the paintwork. :yesnod:

What David said (except the paintwork bit cos mine's rubbish) and better brakes.

Get rid of rust first, then work in the interior. Thats what im doing, first job was to replace the boot lid which was the only area with rust. The cars has the brakes fixed with new calipers and pads and discs to ensure the car is mechanically sound. Now im working on the interior restoration before i start on the paintwork, so new steering wheel which isnt worn out, new seats, door cards and carpets also. Seeing as i spend most of my time inside the car i wanted to get that right first.

As long as the bodywork is in reasonable nick, I would make sure it is good mechanically. :yesnod:
Otherwise you have no trust in the car & are always wondering what's going to go wrong :omg:
Bodywork & paint can be done at a later date as long as you haven't bought a rust bucket