How do I remove kapton tape from soldered parts in bulk?

In order to reduce the size of a PCB, I will probably have to use smaller SM components. I currently use mostly 0805 passives, and am thinking about going to 0402 or smaller. Apart from power dissipation considerations, any pitfalls I should be aware of when making the transition?

I ordered RF PCB design and prototype from my supplier . There are something like a hole, but it is not, on the ground surface. What is the purpose of making these holes? The PCB is inside of the E70 433NW14S LoRa module.

After We have assembled the Virtex-4 FPGA BGA package on our custom design PCB, we check for short circuits between all power grounding and they shows short cut between each other. Please tell us about any process for debugging this issue.