Here's the problem: Some of these effects just wouldn't work. There's also no way to fight mid campers with Ender pearls. Most of the time when you fight mid campers you're stuck without a diamond gen. Therefore, we need something with gold that can fight mid campers effectively. I'd personally recommend adding a 1 minute invisiblity potion so we can try to sneak our way over a bridge - or stack them to try to build a wider bridge across. Just make sure the name tags aren't visible.
Also, thank you for finally adding Ender pearls to normal mode. Now to discuss the potion thingies and more stuff about mid camping:
Potions really have more negatives than positives. Let me explain:
Let's cover speed first. Speed may not seem too bad, if it weren't for one thing. You actually move faster without jumping if you have speed than with jumping. This doesn't seem too bad, but it becomes problematic quickly. Chasing people down would be a NIGHTMARE as they're moving faster than you AND they're losing less hunger. Therefore, speed
If you can come up with a way to counter campers at middle, then I'd happily implement it, but if there at middle, they have access to all generators, they technically should have more power than you and the next move should be up to them.
Adding invisibility so you can "sneak" up on them would be way to powerful. Mostly because if there was invisibility, protecting you egg would be pretty much impossible, as you can just sneak around islands and break eggs.
So I stand by my point, if there is a team that is just staying at mid, it should be their responsibility to come and attack your egg sooner, if they're not attacking your egg and focusing on protecting their egg, then they're simply playing by the rules of the game. If you don't like this style of game play, I suggest that you play on a different map, for example a map with more islands that offers the options to bridge sideways to other islands rather than directly towards the middle.
As for the speed effect, nothing has been confirmed, from discussions that I've had speed effect will not an obtainable effect. The things I'm thinking are more like: Strength, jump boost, regeneration after a kill, haste, absorption and reduced hunger loss. Feel free to comment on these effects if you would like changes making.