The way I used for getting an evenly tinned surface is to use room temp tin plating solution to, it seems expensive at first, but the solution lasts a long time and can be stored and reused if you make too much up.

For tinning, my method is to coat the traces with a flux pen as soon as the board is finished etching, then run all over them with the thinnest coat of solder from my iron.

I use the photo-etch technique and find that the small residue of resist remaining on the board after resist removal protects the copper.

Regarding the cutting of PCBs, tin snips do a good job for me.

Very helpful and valuable.