The good news here is that for the KG electrostatic amps that are often mentioned here (such as Blue Hawaii, KGSSHV, Carbon, Grounded Grid, etc.), there are proven PCB's for both the amps and the PSU's that many have built working and reliable amps with, myself included and I do not have a science degree and never forged a knife in my life!
Extra safety precaution does need to be followed strictly given the high voltage involved! With that said, if you source correct parts from reliable vendors (Mouser, Digikey, etc., not eBay, not Taobao...), stuff the right parts in the right spots on the PCBs, exercise good soldering practice (many good tutorials on Youtube) and pay attention to layout of components (circuit boards, transformers, connectors, etc.) and wiring, your success rate is very high.
On top of that, many knowledgeable people here will come to rescue should some things do go wrong provided that you have done your homework!
It's lots of fun and a very rewarding experience!