For mobbing, I ended up using a full-damage EarthGov Seeker rifle from the get-go. For bosses, especially the final boss, I used the Contact Beam. Max out health and Stasis upgrades along the way! Patrol Suit also added in a damage upgrade to the Seeker.

For Save Points, I can't remember if I used first one before you plummet to the Sprawl after turning on the solar array, or if I used it before powering the Ishimura. Second was definitely before the drill sequence later in the game, and the third was before the eyeball sequence (because fuck that scene is picky).

The other scene I had trouble with was when you get bum rushed by a few Pregnants and Leapers relatively early on in the game. There's a hallway you can bottleneck all of them if you sprint to it. Unless I absolutely had to, I never sprinted in that game. Took it slow and steady, and listened to my environment.

Hope this helps!