What are the best visa options for traveling in and out of Thailand after an ED visa?

Hey guy, I would like to ask your for short suggestions to two visa questions:

1.) I am here (BKK) on non-immigrant ED visa (valid till Oct, 26th, no multiple entry). My internship at Mahidol university ends mid-September. After that I would like to travel, with minimum one exit/re-entry to Thailand. (Maybe 2-3x, travel plans are not yet precise enough) My travels will end Mid-October at the latest. Can I simply exit on my current visa and use a simple tourist visa upon arrival when I re-enter Thailand? Only once or also for multiple re-entry’s?

2.) Those 2-3 months here are actually kind of a test if I like it here, since I am potentially free for the time till April 2023 and can work remotely from Thailand till then (that means coming back in November or so) If I decide to do so, what visa should I go for and read further to its conditions? I will definitely need to go back to Germany around April 2023, so kind of 6-12 months visas will do. Multiple entry/re-entry might be useful for Christmas or traveling. I will not have a work contract, only doing some remote work, learning for university tests that are coming up afterwards and such. Maybe permit to work in Thailand would be nice to have thou. Is there a suitable visa I should apply for? I am asking at this point because - since I am in Thailand currently - something with immigration department or such could be more easily/conveniently organized while still here till October. (For example: This new visa, if valid for 12 month could also start in September which would do till April 2023 and might as a sideeffect make travel plans easier, see #1)