All watts herein are in RMS. What I have...
AMP JL XD700/5
75w x 4 @ 4ohms or 100w x 4 @ 2ohms

4x DXi650 coax door speakers
60w @ 4ohms each

I planned on just connecting 1 DXi650 to each channel and leaving the additional factory 2 front tweeters and 2 rear 3.5" speakers disconnected. This leaves me with 100% power going to the DXi650's and my amp is not maxxed out.

While reading up on car audio, I am now thinking of replacing the stock tweeters and 3.5" speakers with DXi1000 and DXi350 respectively and wiring them in parallel with the 4 DXi650 door speakers already purchased. I.e.

CH 1 (Front Left,100w @ 2 ohms) - DXi650 (60w, 4ohm) and DXi1000 (60w, 4ohm)
CH 2 (Front Right - everything else same as above)

CH 3 (Rear Left, 100w @ 2 ohms) - DXi650(60w, 4ohm) and DXi350 (35w, 4ohm)
CH 4 (Rear Right, everything else same as above)

Now the amp will be stressed to it's max and I will have more total watts and speakers, but they will be under powered by roughly 10-20% (10watts each) with the exception of the 3.5" DXi350 (35w rated) which will be getting 50w power.

Questions...

1) First off, I am new to this and am assuming I can wire these speakers in parallel. The speaker manuals did not specify. Can these speakers (all rated at 4ohms) be wired parallel into 2ohm loads without damaging them?

2) Would the second setup with more speakers in parallel provide better fill and sound?

3) Will the 3.5" DXi350 be ok with 50w? Is there something I can install in line with those that will reduce the wattage they receive to within rated specs of 35w?

Thank you for your time