Thanks for making such a considered post as well as providing a mechanism to pass on feedback.
I agree with more or less everything that you have said. I'm not opposed to mods in principle, nor am I one to cry "cash grab", nor am I opposed to change in games -- if done well, it keeps things fresh.
However, in my view mods go far beyond a refreshing change and have completely disrupted the entire game -- very negatively. Even if I give the benefit of the doubt and say "okay, let's allow time for a new feature to settle in and be tuned", I struggle to see how this can work out well.
My main grievance is that it renders many styles of play and evenh weapon classes essentially redundant. You brought up sniper weapons:
"...and how they end the dominance of sniper weapons..."
I completely disagree with this and this is borne out in the game statistics (I wrote a little API to collect results from matches, I won't get into that here but I can post it elsewhere if people are interested) as it is not sniper mechs which are consistently the top scoring mechs.
Mech Arena, has always been far more heavy on the missiles, homing weapons, and artillery style of things. By definition, there is less emphasis on the player being accurate, as either the homing mechanism does the lion's share of the work, or if you miss you still get splash damage. That's not to say they are a skill less weapon, the skillset is just different.
Sniper weapons on the other hand, have no such luxury, if you miss you miss hard, they are a linear weapon and have a low rate of fire. The trade off was if you were accurate, your accuracy was rewarded with high damage. In a game with maps that are relatively small, and already dominated by afore mentioned artillery style weapons snipers were already disadvantaged. That was fine by me, as I enjoyed, and got a kick of a well placed shot.
With mods the reward of high damage for accuracy has completely vanished, especially with the multi layer shields. There is no incentive to use sniper weapons at all, they just aren't effective. I think this can be said if any slow rate of fire weapon, whether it's a shotgun or a sniper rifle.
Many people have said the player base will adapt, and they are right of course, but I think it's a shame to render entire styles of play and weapon classes useless. Maybe in there will be a "renormalization" in the future with weapon mods or something and we'll essentially end up where we were pre-mod, but with an additional currency (mod parts). But until some refinement, for a player like me, who was less interested in winning tournaments and just enjoyed supporting as a sniper, the game as it is now holds no attraction for me.