Wiring question for replacement of two switches in one box
Currently the white neutral wires for the one incoming line and two loads are all bundled together with a wire nut. It would seem I need to use the jumper wire which came with each switch and merge both with the existing white wire bundle then attach the other ends of each jumper to the neutral terminal on each switch.  ... And the last question is whether I can use any copper wire to run from the white wire bundle to my switch? I seem to have misplaced the jumper wires which came with the switches


I think you have the right idea.  You'll want to attach a short piece of wire, a pigtail, to the neutral terminal on each switch, and splice those with the three neutral wires already in the box.  You should use the same white wire and the same wire gauge for the pigtails.  There is a good chance the existing wire nut won't make a good connection for you with five wires.  I'd suggest a push in wire connector that will accept all five wires.  




  Another thing to mention is that the line wire is connected to the line terminals of the two switches in an interesting way. A small section of the wire about 6 inches from the end is stripped so the copper is exposed and that exposed section is wrapped around the screw of the line terminal on one switch then the end of the same wire is connected to the line terminal of the other switch. I want to be sure that this is an acceptable setup. 


That's an acceptable way to make the connection, just make sure the wire is in good condition where the bare spot was stripped off - no nicks in the copper etc.  If the new switches are bulkier than the old switches, and that jumper is short, it may not be long enough to make it from terminal to terminal.  If that's the case, you can just pigtail the line side hots (blacks) the same way you did the neutrals.