So...
Reddit was marginally helpful. Basically, I was advised to farm for better gear at a lower difficulty with an alt, but that seems kind cheesy to me. The other advice I was given was to pump everything into my DPS stat (which would likely be Focus for Seismic Slam or Emberquake). However, that would nerf me for gear, block chance, and a couple other useful things.
That being said, I decided to push through all the bosses in the Temple Steppes. It turned out to be quite easy, but sooooooooooooo tedious. Beatrix actually plays almost exactly the same as Eiko did. The only difference is that instead of kiting and spitting mines, Beatrix is kiting while dropping Seismic Slams so that whatever chases her pulls some fire DoT. And, when I say it was tedious, I mean, teeeee-deeeeeee-us! It took forever to take down Modrox and Grell. SS' DoT is effective, but very slow. I think I spent about a half hour on Grell. In the meantime, I took next to no damage and my Forcefield timed out far more than it broke.
This is couple with something I noticed with the controls that is much more perceptible with a melee build. So, the mouse will interact with whatever wherever you click or something nearby if it's "close enough" and the game has a very liberal definition of "close enough". It wasn't as noticeable with my ranged/minion builds because I was far away from the action and had plenty of open places to click in order to move. However, being close range with melee and having a screen full of enemies means that most places I can click are "close enough" to advance on an enemy and attack, rather than run away and kite (which is usually what I'm trying to do). It's very annoying and inconvenient and could be potentially lethal, but I'm managing.
This has me questioning the concept of a challenge in this game. I don't know if challenge can be found in the playing of it. The controls aren't that refined and the builds lend themselves to simple playstyles. Effectively just slowing down clear speed isn't a challenge. Maybe challenge is to go in the opposite direction. Aim for optimal efficiency and then play is just a meditative semi-idle experience...kinda like watching a
Game of Life unfold.
Beatrix is definitely not optimal. So, is it Eiko (pure summoner) or Rebecca (Tank Girl). Rebecca definitely can put out more damage since she's supporting her minions with a cannon, but she's sacrificing defense to do so. However, Eiko's defense superiority comes primarily from her shield, which is really only a backup defense when/if her Forcefield fails. Eiko has another advantage though. Due to the "close enough" clicking, Rebecca will accidentally engage and attack (which has a pretty slow animation) far more than Eiko (who will start to advance, but I can stop pretty quickly).
Conversely, Rebecca is more skill efficient. Or, she can make better use of skill points. Eiko quickly gets to a point where more skill points does nothing for her. So, her skill benefit plateaus long before she maxes. Rebecca has a higher ceiling for her skills. And, the same goes for her abilities. Eiko really doesn't need any stats and Vitality is just a dumping ground for a boost to block. However, there are actually ways to max block without even putting a single point in Vitality. Rebecca can go pure Strength, and she is actively using this benefit.
I think Rebecca pulls out ahead. She'll be a bit harder to keep alive, but she won't have to worry about any DPS walls. At eight max skills, and 13 points to spare, that's probably Heavy Lifting, Healing Bot, Blast Cannon, Spider Mines, Gun Bot, Sledge Bot, Forcefield, Immobilization Copter for my max skills and maybe throwing a point in Storm Burst and the rest in to Coup de Grace for a slight damage boost with the cannon.
I'll have to think about this more.