Can I use fractional tempos (tempos with resolution finer than 1 BPM)?
It is indeed possible to have tempos of finer increments than 1 BPM. However, you can't do it from the main tempo page. What you have to do is actually record a tempo event into the sequence, then edit it. What you do is highlight the tempo parameter, start recording, and then either type in an amount or move the wheel. (Either record onto a blank track, or use an existing track but have the record mode set to merge so you don't erase the events already on that track).
Once you have recorded a tempo event, if you go into the Event editor, you will see the tempo event (it will show up on all tracks). You can move it where you want, and you can change the value. You will see that you can enter fractional amounts.
Need more info? Check out the following links: