What you should know?
If you go with Gauss, Multiplas, Plasma Caster and Laser RCW you are perfectly fine to finish the game without much hassle. Make sure to build your character for criticals, you want to maximize your crit% meaning 10 Luck after an implant and Built to Destroy are very much desired. Fast Shot is something you want to seriously consider over Trigger Discipline, spread on Multiplas or Tri-beam is nowhere near spread of real shotguns so they aren't as affected - and you want to be able to fire as many shots as humanly possible to get more kills with criticals. Top that with Finesse, Better Criticals, good Sneak value and you are rocking it.
Don't take Metldown unless you also picked another skill Unarmed or Melee. Get Pushy for example with Piercing Strike and you are able to fend off V34 security or whoever gets in your face. I've played a Paladin (unarmed + energy meltdown) and it was a stroll through the game.
Pick Vigilant Recycler, make sure 20-30% of your ammo is MC for tougher encounters (don't bother with OC until the patch) and don't shoot MC at armored targets (proven pointless). Your character demands Jury Rigging and you will need regular trips to Fiend territory to gather their weapons to repair your stuff.
Best companion is most likely Raul, he prevents item decay (some weapons are really hard to maintain, like Plasma Caster or Tesla) allowing to MC the crap out of enemy and still not have to run down Fiends as often. You also could take Gannon for a Gauss team or Veronica and dress up as the Brotherhood.
Top that toys like Pulse Pistol, Pew Pew and Euclid and you are looking at a lot of fun.