The speed and ticks concepts confuse me. I’m not a math nor a logic person, so don’t bother. I’ve read the wiki sections regarding that matter and I’ve decided that I can live and make music without a full understanding of the difference between tick based and time based sequencers. 
BUT I’d like to know two things :
peace
The next edition-release of Renoise will support exact match user-bpm.
1.5x won’t have this feature.
Some bpm rates in 1.5 matches equal supplied rates just because the tick error quantasion calculation comes with a clean bpm rate for those rates.
Just wait until after summer. (just a guess btw, no promises made!)
Nice!
Euh, what do you mean exactly by that? It’s getting too technical I fear… 
the thing about tickspeed an bpm is this:
ticks are used for timing, so if you have a tick of 6
then each Pattern Line ticks 6 times Before moving to the next Pattern Line.
So, when you have a speed 1 you do get the Absolute Maximum of Pattern Resolution, since it is ticking only once per pattern line.
If you make something at speed 6
and play it at speed 1
it will sound like it is playing very fast,
but it is not, because it is only playing 1 tick per pattern line.
BPM is your actual bpm. (only atm we cant control the remainder(0.123))
“how many ticks per pattern”?