For the tape job configuration, which settings i should choose?
It depends to the requirements you have. Answers to the following questions should clarify the situation. How many restore points you want to store on tape mediums? For how long? How often you're willing to rewrite mediums, etc.
Can i use the same pool (only 1 drive) for both full and incrementals?
Does it recognize synthetic full vbk? Meaning on the day of synthetic full backup file created, it will be pushed to tape automatically.
Are we talking here about files to tape job or backup to tape one? The newly-created file should be recognized by both - in the former case, as a new full backup, in the latter, as a new .vbk file.