I'm really strugging with money in this mod. I always seem to hover around ~300-500 caps, no matter how much I sell, because I'm buying repairs/ammo/health/rad cures/etc. Level 7 at the moment, and house upgrades seem far away. My barter skill is only 17. Should I upgrade this? Are the exact FWE changes to barter listed anywhere? The readme only has 3 short sentences on the subject. I've been dumping skill points into science/medicine/lockpick/repair/small guns so far, with a little also in speech and melee.
Focus on skills that will keep you alive early on - your primary combat skill, lockpicking or science (to open locked containers or hack computers - you never need both), and either medicine or repair. You could also take explosives instead of lockpicking/science, but using grenades and mines really, really helps even things out in the early going, especially if you're running optional mods like increased spawns and harsher wasteland, so you don't wanna have to use them all up to open some dumb chest to get 30 caps worth of ammo or a piece of scrap metal. Barter and speech are nice, but talking pretty and getting a good deal won't help you if you died because you couldn't fight properly.
Try to sneak over and grab Dogmeat at your earliest convenience - if you have the followers mods installed, he can't die, and he makes a wonderful bullet sponge for the critical few seconds during the beginning of a fight, and this is especially true if you're a melee fighter, since you'll tear people using guns up in seconds once you get close.
If you're a melee fighter, use guns against enemies using melee weapons and melee weapons against people using guns (caveat: rushing someone with a decent automatic weapon, flamer, or minigun will be bad for your health) - having to time your attacks and blocks to land a successful hit on another melee opponent takes too much time and will result in you taking too much damage. Pull out your pistol, shoot them until they drop the weapon, then finish them off.
Your house upgrades are just luxuries. You can use the workbench in Moira's shop, Doc Church doesn't charge too much (hint: if you want to lower the price, go heal yourself by sleeping or eating first), and you aren't gonna spend enough time in the place for it to matter if it looks pretty or not. Assuming you're using primary needs, your first extraneous purchases need to be the RobCo grill and water purifier, because grilled meat weighs less (and heals more) and drinking dirty water instead of good water will rack up rads fast. You'll get plenty of energy cells when you knock over the Super Duper Mart, and Rad-X is generally pretty cheap.
If you need cash in a hurry, go to Minefield and sell the mines instead of keeping them. There's a ton of the svckers there, and they're worth a decent chunk of change if you don't think you're much of a trap-using type.