LOL:TPS to Greencard easy , no interview nothing direct greencard
No matter what you have to go through interview process for GC
There will be no red flag if you are you planning to leave F1-Status , just make sure that you have informed your college that you are switching to TPS status .
For example: When my OPT expired I already got my TPS approved and then I filled for I-485 based on employment and I put my current immigration status as TPS.
If immigration officer ask you what is your current status just tell TPS and before F1 and you are maintaining your status legally since last port of entry.
Please look at the link below for TPS to GC timeline: