Quite a list there! If the aluminium (or copper) washers don't fix the leak on the banjo bolt, try Dowty washers instead.
https://www.ebay.co.uk/bhp/dowty-washers
You'll find they are quite tight around the bolt as in you'll pretty much have to wind them down the threaded part but often they will seal where ordinary compression washers won't. In fact, on one of my chariots they are specified for the sump plug and gearbox drain plug. Both the same size so i found a hydraulic hose supplier and bought a bag-load of M14 Dowty washers cheap for cash a couple of years back.
As for your oil leaks, once you've cleaned the PCV system, try adding some Carlube ATF-U to the engine oil. It has a compound in it to revive and condition rubber seals so could well get rid of a lot of those leaks. It will also gently clean the internals as well and help free off things like sticky piston rings.
