Bubbles in epxoy or other resin can be removed by sliding the container back and forth rapidly, or using an ultrasonic toothbrush, or setting it on a running washing machine, that sort of back and forth movement brings them to the surface. It may not make it bubble free but it will get rid of a lot and localise the remaining ones in a line that can then be avoided.

I think xylene can also be used to thin epoxies. Proprietary epoxy manufacturers supply their own thinners, i bet if you checked the MSDS sheets for those thinners you would find some clues