You're hurting your own cause with this idea. You do this gun weight thing and you'll have people talking about how they never pick certain things up or buy certain equipment combinations because of problems with avoiding aliens.
The problem you are saying newer players have is that it is too hard for them to catch up to humans who are wearing heavier stuff. If the problem is purely mobility, then I'll tell you right now about how I could just drop all my equipment given your solution and naked rifle enemies all over the place, as could plenty of players...and we've done it before, easily. What's your solution to that absurdity?
People need to face the fact that, given the way this game is at its core, new players are going to have to hit the game at a crawl and get raped a bit before they learn. You act like the game is being made for babies who will never improve if the game is too hard, even though 1.1 (the unquestionably more skill intense version) brought in its fair share for the earlier days of its run. People sucked it up and learned. Then GPP comes along with its "noob-friendly rebalancing," and it turned off a huge amount of 1.1 players because of these changes. That version already lets 1-week players get the upper hand on you even if you're not making any mistakes, which is ridiculous.
To add to this specific case, it helps to discuss how things were and how they are now (I'll stick to talking about 1.1 -> GPP, as Unv has more to come and no one's playing it). In 1.1, it was eventually determined by those involved in GPP's development (at what was known as MGDev server in 1.1 at the time) that it was too difficult for humans, in general, to dodge alien attacks. So, on the human side of things, dodge was added, along with various changes to alien attacks. Now, in GPP, dodge is overpowered vs. dretches, marauders, goon chomps, and tyrant slashes. Now you're telling me that it's too hard for the aliens to catch the humans, even while goons and tyrants both received enormous buffs to their movement based abilities?
Adding shit in to counter other additions has already shown itself to be the less favorable route when removal or base numeric changes are possibilities, given the states Tremulous has been in in the past. Try not to start such a thing up again. I agree that the game should have noob-friendly elements, but these should help them learn, not kill, within a balanced environment. But I think the game should be balanced for your standard players with a bit of experience, not for noobs. You balance the game for noobs and you'll either end up with no one really getting any better or players heavily exploiting the noob-friendly elements.
Don't give me that "has to be more noob-friendly to be popular" bullshit either. If people coming into the game really badly need help to play, someone can set up some kind of training server or something. But I think if I started hearing about people not playing the game because it's "too hard on humans" even while standard players vs. standard players ended up balanced and fine, I'd put the blame for a loss of new players on those players, not the game.
Anyways, while very little Unvanquished has been played, it went active with some balance changes that I predict will work out fine, though some need tweaking. The dragoon changes (chomp buff, pounce combat nerf, movement speed increase) and dodge being nerfed are the two most significant ones, though the goon movement speed could possibly use slight alterations. Me and Ishq had a devmapped 1v1 to test some things, and it's pretty much like 1.1 mixed with GPP, only humans are no longer able to just run (1.1 and GPP) and dodge (GPP) away.
For tl;dr: Don't add random shit like gun weight to counter other additions (i.e. dodge) for rebalancing purposes, and don't balance the game towards noobs, balance it towards "standard" players.