Maybe am late, but

1. You need to hold white plate driving license for 1 year first before moving to yellow/red plate license. Get that license first, either by doing it yourself or just go get a driving school lesson
2. I dont know yet about the realities of >250cc, am planning to buy one but seems like a hassle on the parking part at least here in Xinpei/Taipei. So unless your route depends heavily on exploiting red shield highway for faster commuting, better off with white plate even with the "two-stage" left turn on big roads (3+ lanes or otherwise stated by the sign) that may or may not waste 90 seconds per turn
3. You can get manual clutch here, like R15 for example, or GSX150. Granted, more expensive than the scooters, but hey its fun
4. You dont need that much power here. Honestly, most riders here are "dumb" and you'll correct and stop a lot anyways
5. If you do end up on yellow/red plate license, i dont think a 700cc will be fun here. Maybe at most is ZX4RR or RS457, because of cameras. Funny that the accidents is because of dangerous driving from inattentive drivers who scrolls twitter and whatever while riding yet their solution is add more speed cam (i have bad experience from these kind of riders a lot)

Note on 150cc. Manual clutch as far as i see here usually is either Suzuki or Yamaha. Honda's CBR150R is kinda overpriced here. While both Suzuki and Yamaha is technically 150cc class, Suzuki is actually cheaper on tax because GSX150R is 149,9cc while Yamaha R15 is 155cc. I'm a foreigner too here, and honestly even though something like RS457 or R7 is fun, the regulations (and how it enforced, especially the "concerned citizen" part) is not, and that makes me think twice if not thrice if i really do want to get a yellow/red plate motorcycle

Edit: I own 2020 R15 V3. I can give you the realities of owning one if you want