You should be using atleast regular tourist visa not exemptions. If you're going to your home country either apply for a 6 month multi entry tourist visa. If you get the last 60 day stamp just before it expires you can get 8-9 months out of it without questions or even better get a DTV visa using a soft power and don't worry about visas for 5 years.
I stayed in thailand almost 2 years on 6 month tourist visas and such then recently switched to dtv. They will most likely ask you about your employment to make sure you aren't working illegally in thailand. I showed over a million baht in the bank and applied under soft power, but they asked for additional documents showing how I earned money outside of thailand and brought it in. I showed them deposits/withdrawals from my us bank I use to receive contracted work payments and that was enough. So long story short if you've been in thailand awhile be prepared to show how you have been and will continue to be able to support yourself without working illegally in thailand. As for taxes over 180 days you are responsible for filing taxes in thailand, but some countries have a tax treaty so everyone's situation is a little different. For usa we get credit for the taxes already paid on income in America and would be responsible to remit payment for anything owed beyond that based on thailands tax brackets.
Don't forget your 180 days has a 90 day report to immigration. The stickers you see isn't the stamp it's a physical copy of the visa from someone doing on person not evisa, but they are the same.