Future expat needing advice!

Hi there, So long story short, my husband and I are planning on relocating to Thailand late 2018, I am a online English teacher, and my husband does online transcription. We have lots of questions about the process of relocating and whatnot. Any advice helps. So since we both work for online international companies, do we still need work permits? Or can we simply apply for a retirement visa and show we are receiving money outside of Thailand? I have also been accepted into a thai university for a bachelors degree in teaching which in 3 short years allow me to apply for a work permit since I will have a degree. Do I need any specific visa that allow me to attend a school in Thailand?
We currently live in a one bedroom apartment in Canada and plan on selling almost everything we own and just bring a suitcase and our cat. Has anyone relocated with an animal? How easy was it? with all the correct papers did you have any difficulties at the boarder.Do we need to buy a return ticket. our budget will be around 1,200 CAD every month. Both of us make aprox 1,500 every month. Please if anyone has any suggestions on relocating, things we may not be aware of, please let me know. everything helps.