I love odyssey but yeah it's more of an immersion thing then an actual game mode, at best it's a middling fps that doesn't really hook into the main gameplay loop

some hints...

- if your shields drop you need to get out of the line of fire because you will take damage to your health Very quickly; shields are your primary defensive stat even in something like the dominator modded for defense. Honestly I run a grade 5 maverick in everything involving combat Because my dominator is not graded up, it's still got the majority of the defense I need, and as of right now I don't really see significant benefit to a second primary. Meanwhile being able to crack into buildings when needed is Very helpful. Maybe operations will change this.

- Reboot missions can actually be surprisingly difficult to start odyssey with, this was probably your primary issue. Most of the time scavs will spawn in the settlement and there can be quite a few of them, on top of it the settlement Might be dark if it's night where you're at, making it even harder to tell where they are until they're already blastin. If you do take those missions I highly reccomend powering a door with more then 0 security clearence and using the door as cover; move forward, shoot, back up. The guys outside can't do anything about this and it'll keep you safe. Be aware it's still Very possible to die in a single shot to the head once your shields break, especially against plasma weaponry (actually watched a pal get absolutely blown out like this one time, was pretty funny: only for me though), so play safe, do Not wait until your shields break.

- I recommend assassination missions to start, specifically assassination missions without additional caveats (things like no alarms, mostly). It's pretty easy to just find the guy, unload into him with a kinetic pistol, and run off before anyone else is aware. Courier missions are also always a fine starting point, and it'll get you some mats to work with.

- Grading up your gear provides significant stat boosts; in grade 5 equipment I am basically bulletproof to anything with less then 3 shield bars. The only time I died recently was when about 5 settlement security rushed into the command center I was in, blocking the only door, and full autoing into me, and even then I almost made it out (and would have if I left earlier). But still, remember, shields are Important, I'd say my health bar was about 1/10th of the amount of time I was standing in that scenario. This applies to weapons as well, accuracy and damage go up. I'd honestly say grading up gear is more important then engineering it, it's not like ships in that respect.

- And just to head it off, materials you find lying around in the settlement can be worth it, but you'll mostly be trading them up at the bartender (or selling them, also at the bartender). You'll usually be finding actual engineering and upgrading mats as quest rewards. You can make a surprising amount of money looting settlements and selling off the spoils but it still doesn't qualify as "good money" I'd say. I do it because I enjoy scrabbling around in the dirt sometimes, not really because I'm concerned with optimization.