I, as most of u would now know, have a Qu-ax 24" Muni, but i am also keen on tricks, not just mountain riding, so is it possible to learn ALL the tricks a trial/street/freestyle uni can? 
ya pretty much but it takes mor practice…like for unispins the uni is heavier so you have to work harder. and stand up or foot on frame tricks are also harder because there is less space between the seat and the crown.
No, tricks like side riding don’t work with long cranks, cross-riding can’t be done with a too large wheel and unispins and pirouettes don’t work if your tyre is too chunky. These are mostly the higher level tricks, stuff like 1ft wheel walk etc. can all be done, but they are a little harder on a Muni.
You can learn most tricks on a MUni, but some of them, especially freestyle ones are going to be far harder to learn. A knobby tire and pinned pedals make some things really awkward or dangerous. Side-riding does actually work all right with longer cranks, (I learned on 150s) but short cranks really make a difference for a lot of freestyle tricks.
So, if you want to do easy stuff in all genres, your MUni should be fine, but when start moving toward more specific advanced tricks, you really should consider getting a freestyle and/or street/trials unicycle.
I disagree…all tricks can be done, just considerably more difficult.
I have myself and seen many people one-foot and wheel walk a MUni. I have seen Irene Genelin stand up one foot wheel walk a MUni downhill in the dirt. I have seen Kris Holm sideride a MUni with 175 cranks and glide at speeds high enough that smoke was pouring off of his shoe.
Let me disagree.
I can do unispins on my 24" Nimbus Muni. They are a bit harder (the 180 unspin, that is) but they can be done.
Other stuff like pedalgrabs, crankflips, grinds, gliding and 360 can also be done on a 24" Muni. But you will have to be stronger to pull some of that stuff off.
Strength is only necessary to overcome poor technique. My Jedi master Gerblefranklin is only slightly larger than master Yoda, yet he can pull insane trials moves on his 24" Muni. He may never win an arm-wrestling competition, but he pulls rolling hops over cars. The long way. While in traffic.
I thought this for a while, until I got to seat-on-side on the Coker. That is a leg length / wheel size issue, not a matter of finesse or strength.
I agree that the leg length/wheel size is a factor for doing certain tricks, therefore certain tricks CAN"T be done on a Muni especially if the person has really short legs. One trick I can for sure think of is cross-over (your leg would have to bend in an impossible position in order for you to do it, especially not to hit the tire and scrape your skin off-it’s hard enough on a 20" freestyle with a smoot tire).
So most tricks you can probably do on a Muni, but there are some that I think you can’t.
I’ve never done trials, until now. I have two unicycles; a Coker and my new '06 torker dx 24" that I bought mostly for muni. I’ve have been using the dx to try to learn trials, but I will say that using the 24" for trials is kinda like using 2 or 3 bats to warm up! When you finally pick up the one bat (the 20" Metaphor) it’s a breeze!
Apologies, i meant the trick when you ride in a very small circle that usually preceeds a pirouette, I can’t remeber its name right now.
A spin?