I have no opinion yet on the latest changes overall since I have not tested them but I am fine with a nerf to Bulwark in principle. It was boring to almost always choose it over other possibilities.

Regarding difficulty, I have found through many play throughs myself and watching mnay play throughs by others of various levels of skill that the story was tuned a little bit too easy in my opinion. It was extremely rare for skilled players to lose a mech or pilot even at high difficulty settings. It was common for less skilled players to lose multiple mechs and pilots even with Bulwark available to them. Thus I don't think having or not having Bulwark will make that much difference in the overall success of a player. It may make the game slightly more challenging but I think that is okay. Some settings changes are still available to make the game easier or more difficult than the default for those that want to use them.

The main differences between the skill of players is not in the selection of skills. It is mostly in how mechs are used in battles with the standard mechanics available to all. Customizing mechs in more optimal ways plays only a small part. Skill choices and ship upgrade choices play a very small role in difficulty. The main thing is not losing mechs and skilled pilots which forces some regression. Skilled players know how to make choices to minimize this. Keeping damaged mechs and injured pilots in safer positions. Waiting for slower mechs to catch up and pushing forward in groups. Using reserve to delay actions so that you are in a better position than the enemy during contacts. Making use of morale based special abilities as often as possible. Using terrain to advantage such as staying in cover, using high ground, and blocking line of sight when appropriate. Using scouts to do their job of identifying targets at maximum range without putting them at unnecessary risk. Using long ranged fire on sensor locked enemies to soften them up. Choosing where to fight so you can focus fire and delay contact with some enemies.

I have watched players improve significantly by changing tactics even when they opted not to take Bulwark on most pilots. I have tried it myself in play throughs where I avoided Bulwark as a handicap. It was very powerful to be sure but the success or failure of missions and the story were primarily dependent on other things. I understand that the game will feel too difficult at times for some. For these players though, having the old style Bulwark is not enough and once they improve their skill level by learning better tactics they would not even need it. Hopefully these changes will make the game more interesting and fun without turning away those who relied on Bulwark in the past. I don't know if I like the changes yet but I am willing to give them a try. If frustrated by difficulty my advice is to adjust tactics and use everything available and keep trying. You can do it.

The engine is at best only partially to blame - as you rightly point out, there have been other games made with it that have more going on and are better optimised.

The problem is that the devs didn't seem to learn as much from Shadowrun (assuming at least SOME of the devs are the same) as one would have expected. Simple things like it taking ages to sort lists, display saved games, etc. - these things don't require complex coding, but a bad understanding of coding can definitely make simple things such as this worse.

Even if one were to say "this engine isn't suited for this scale/type of game" - remember that it was (hopefully) chosen by the devs - so if it's not good enough, then they should have gone with something else (such as UE3/4/etc).

Sure, one could say "the 4 mech limit was a design decision, made independent to (and/or prior to) choosing an engine" - but that instead points to bad design. This retarded idea of limiting squad sizes to such pathetic numbers limits tactical options, and is why XCOM and XCOM2 are (IMO) steaming piles of crap prior to LW/LW2 mods being added.

I actually agree with this - like in most games these days, while skill selection definitely affects the difficulty of missions, it generally changes the difficulty from "ridiculously easy" to "slightly more challenging".

For most of the campaign, I was able to get through most missions without casualties. Without Bulwark, I found that I actually had to pay attention to cover, concentrating fire, etc. - as opposed to just attacking whatever was in range without thinking too hard.

This was probably due to hit ratios being far too high overall. this affected the enemy too, but the AI isn't exactly sophisticated - it tends to react to current circumstances, and doesn't really plan any moves ahead at all as far as I can tell. Actually even in the same turn, the AI often failed to properly coordinate its forces (I'd often see it do stupid things like scanning a Mech after all other Mechs had already had their turn, for example).