Yeah, I suppose that there isn't too much need to have the blades that early. The Phantasms aren't too much of a problem especially if you're using sidestepping to maximize your speed. Gorfiend and I got through just fine on TC.
In regards to the cooperative lua script, we started using it, but it made the game too easy imo with shared weapons and ammo (though we did have fun on Hell Hole using the teleport function to set up some skeet shooting with the SPNKR). Having a teleporter as a safety measure in flooding levels would be logical since it would be a problem the designers of the installation would have had to worry about when designing it. Naturally, you wouldn't want to have it on This Message Will Self Destruct, but perhaps you could make it so that the plasma lowers again after it's had enough time to finish off someone with full purple shields, and make a trigger for a spot on the floor in that room that starts the plasma rising again. It wouldn't make much sense in the context that the ship is exploding and you need to leave now, but the players likely to complain about it shouldn't be the ones that suffer from something like this. If nothing else you can just say back to them "Haha, you died
" Then again, technically speaking if you're caught in a situation like this, then you've failed the level, and therefore have no reason to be catered to. My thinking for this was just to preserve a good net session, because between the two of us if the level loaded properly, then lock-ups were rare on the same level. It's about making a compromise between logic and reality. Personally, I think it's OK to make these additions for Co-op, but I wouldn't touch single player, because single player is the definition of Marathon's story. However, I don't know how much control you have between Single Player and Cooperative versions of the map.
The main thing we've had problems with is frequent lock ups over net play. Sadly, it seems like an inconsistent problem. With the exceptions of Unwired and My Kingdom Pfhor a Horse, we completed the entire scenario continuously over Marius Net and join by address, we had to use JBA after the occasional lock-up removed my ability to host on Marius Net or perhaps the server just went down, so the cooperative enabled project is coming along nicely.
Truthfully, if you use MML to set starting weapons for players, it doesn't force them to use those weapons. Remember, the point of viding is to have have style while doing it. You don't have to give gobs and gobs of ammo either. Probably the biggest threat to viding is the fact that the Chronus Fusion pistol is so powerful, but it's the only reasonable long range weapon you can use. It's been a while since I've played M1, 2 and Infinity, but you might want to check that the scaling of damage to health per total number of shots is the same, or same-ish, if you haven't done so already (ie if you buffed the health of enemies by 2x or so, and the Chronus Pistol gets 3/4 of the ammo that the pistol in the original Marathons got, then each Fusion pistol shot should do ~8/3 of the damage of each original pistol shot). You could argue that the fusion pistol can't be balanced like this though since it's supposed to do extra damage to mechanical units. Though, I believe that each scenario has its own style of game-play therefore leading to different styles of viding, so I'll be ok with however you decide to do it.