Going back to if you will get destroyed by the 'better players' and their speedball guns etc.....
The equipment doesn't make a player.
You have an egrip so in theory can put pretty much the same paint in the air - a speedballer would be limited to 10.2 or 10.5 balls per second at a tournament and maybe 15bps. If they go for semi auto and the rules are for 'uncapped semi' (no limit on bps) then they can shoot more bps if they have finger skills
If you have finger skills then so can you, other than the physical limits of your bravo. I think your egrip will do between 8bps and 12bps
You will all be limited to a velocity of about 280 feet per second. So other than having it a bit lower because your gun/barrel/paint isn't as consistent against someone who is a perfectionist with a well maintained and sized match combination who keeps closer to the 280 limit then for balls in the air as far as the gun is concerned you're all reasonably equal
A speedball gun will be lighter and more ergonomic then a bravo one. But that counts for fractions of a second and gives them the edge when getting their gun up - in the woods that advantage doesn't help them get around the trees and bushes
It does help them to be quicker to react if you meet them up close
Experience will help them, but you will have the luck of a new guy, you won't necessarily act in ways they expect, you wont be an expert in knowing the good spots, but you may find them
It takes one ball to shoot someone. You're one new guy, there will be regulars on both sides, they are shooting each other too
Go out there and try it out. A walkon will be more intense then a punter game, you may find that walkons aren't for you, or you're not ready for walkons yet. You won't know until you try
If it's not for you then there's plenty paintball to play - walkon, scenario, big games, woods, urban, one offs
The chances are though that you will find intense games but fun people, get the chance to chat with the guys, take the opportunity to check out their gear, and go home counting the days to the next game