Yep you can fit rear door handles to the front doors, as long as you have remote locking. If you open the door, you'll see down the side of it that they're just held in with 1 star headed screw, so easy enough to swap over. I've fitted a delocked passenger door handle to mine, but left the lock on the drivers door incase the battery goes flat lol.
As for the rear boot lock, on my 1.4 SE I took the lock barrel out and smoothed the hole where the lock goes, then painted it to match the car. Was a really nice touch...... until the drivers door lock gave up. With my current Golf I've just colour coded the push button and sprayed the actual lock barrel black...