[leoedin]

Paste and adhesive are spat out by KiCad as part of the manufacturing outputs. It works pretty much the same way other EDA packages like altium do - the extra layers are part of the part footprint. If you don’t design your own footprints it’s basically no extra work to generate those.

You almost certainly could do it - obviously with some time investment. Getting multi layer PCBs made is surprisingly affordable now.