1: yup normal filler is fine, however, if you use P80/P120 you'll find it furrs up at the edge of the filler. make sure after your filler works done, you wetflat it all before you primer or it will be rougher than a dogs bollock
2. normal primer, depending on how big the repairs am, cellulose or aerosol is fine aslong as you finish in P180 or P320. if you have 2k then use it
3. is your car metallic? if it is itll need clearcoat, if its high solid you can just spray on the colour which is like a colour/laquer mix that hardens with a shine.