That would make more sense, IMO the non-turbo form of the 45 man's are probably say x2 variance of a standard stt. I'd expect however still to look at a 100bi if you plan on running them multiple at a time.
I'm a little confused by what you mean on this question however:
should you have a seperate roll if you are grinding another form of poker other than SNG on the side?
Do you mean you would maintain two seperate roll's based on if you were grinding cash and sng's? I wouldn't imagine anyone is truly "grinding" both at the same time, I mean I have played both at the same time but its usually maybe a couple of tables of each with some freerolls
running but even then I would expect all rules still apply in regards to go with which ever requires the higher bi for your br.
If playing 1.5 sng and have 100bi for 150$ then you are not rolled to play any higher than 5nl, and if your mixing them up that way I personally probably would stick with 2nl but it depends i guess. Usually when it comes to "grinding" your either focused on one or the other, but again I don't really have a br anywhere at the moment >38$ so I'm barely properly rolled for anything besides 2nl on that site.
I'm sure danial may have more input for you at some point perhaps, in regards to if they are grinding these or not.