Papercuts said:
Another question: For demomen...how do you use them right? I realized how fun they can be but when I go against a demo they usually instantly kill me with a grenade, it takes a few shots for me to do it, so I'm not sure if there's a special way for more damage. And what should he use to bomb jump, the nade or sticky? I saw another demo launch all the way up top on Granary(which actually seems kinda broken), but I can only get myself to launch upward and not really forward.
I haven't played a whole lot with demomen yet, but I've probably played enough to at least offer some basic advice.
As far as the grenade/sticky difference goes, I've found that they're good in different circumstances. I always have my grenade launcher out when there's a high chance that I'm going to have to kill someone fast, like when wandering through the enemy base in 2fort, or through almost any narrow corridor. For example, when on offense on the first stage of Dustbowl I'll have my sticky launcher out while I"m approaching the first point (assuming it's not right after the setup period), then switch over to the grenades once I'm nearing the house.
You can charge up the fire distance of the stickies by holding the primary fire button, too. This is a great way to take out targets at a distance, like snipers or tricky sentries.
And as for jumping, use stickies. One sticky will send you flying if you use it right. If you want to go more forward than up, make sure to detonate the sticky when it's a little behind you instead of under you. You'll also get more height if you jump, then crouch, then detonate the sticky. For some reason, crouching will give you a huge boost (same goes for the soldier's rocket jumps).
Mostly, though, the demoman just involves a lot of practice to get a good feel for the arc of his weapons. It's frustrating at first, but eventually you'll start being able to nail people with the grenades at quite a distance.