Hey Dagredhel,
Yep, Modern characters get two feats at first level, and then a feat at every character level divisible by three. As a result, they've got a LOT of feats by level 20. The class bonus feats are limited enough that it's still nice to have those "pick any feat" feats at 3rd, 6th, 9th, etc., though.
As far as non-combat optimized people, yeah, that gets to be a toughie. I think that there's a sort of different philosophy in d20 Modern, though -- in a sense, it's more realistic. It's HARD to knock somebody unconscious without ANY possibility of them being permanently injured. All those TV shows that have the heroes getting knocked out and then waking up tied to a chair just fine and dandy a few hours later have given people the incorrect idea that getting knocked unconscious isn't something to worry about. Unless it's a careful shot delivered by a professional, getting knocked unconscious almost always has SOME risk of severe damage.
So the d20 folks have made nonlethal stuff a fair amount harder to get off, but at the same time, they've made all that massive damage crunchiness much less lethal. A character who gets taken to -1 hit points isn't really likely to die -- he's got ten rounds of Fort saves to stabilize himself. Whereas in D&D, getting taken to negative hit points meant "You dead, mon!", in d20 Modern, it means "Unconscious, and with some danger of dying."
With that philosophy, I'd say that most non-optimized people pretty much suck it up and take that -4 to hit for lethal damage. If you've got buddies, have them flank, and THEN have them use Aid Another to give you a bonus to hit. A non-optimized person might still take Power Attack -- which in D&D was "feat that the monsters took to use and the players took in order to get great cleave", but in d20 Modern is now "feat that you take if you want to get past someone's damage threshold".
But yeah, basically, you're right. Unless you have at least one or two feats, like Brawl and Power Attack, you don't stand much chance. If you DO take Brawl and Power Attack, you're most of the way there. Or, you could take Combat Martial Arts and Power Attack.
Take a pair Dedicated6 (just choosing one randomly). This hero has gotten in enough fights that he wants to know what to do, but he's mostly a psychology specialist. He's taken Combat Martial Arts, and because he wants to hit people HARD and not wear them down with jabs, he takes Power Attack -- although he's not a good enough fighter for it to be worth it to use it a bunch. That means that (assume a strength of 13), he attacks at +5 and does 1d4+1 damage. Not really a powerhouse. On the other hand, if he has an identical twin buddy, he can use his Improved Aid Another to give his buddy a +3 to hit, and if he's flanking, that +3 goes to +5. The buddy can now Power Attack without fear of blowing his attack, since he's at such a nice bonus, and assuming that he maxes out his power attack to +4, his base attack bonus, he does 1d4+5 points of lethal damage. Do that a few times, you're going to see a 20 -- and that 20 is your damage threshold breaker.
I dunno -- maybe even just using Combat Martial Arts and Power Attack is too much of a min-maxy strategy. I think, though, that d20 Modern is getting closer to real life in that it really IS possible to have characters who just can't fight AT ALL, but who are very good at other things. It's possible to have a dedicated lockpicker and sneak who took every "bonus to skills" feat in the book and therefore has no combat feats whatsoever. And yeah, that guy's toast if it comes to a fight, no question. If you want someone to be able to fight, they're gonna have to buy a feat or two. But given the number of feats you get, including your starting two, your class bonus feats, your normal character feats, and even possible bonus feats from your occupation (Athletes can take Brawl for free, while Law Enforcement folks can take Firearm Proficiency for free), feats are a lot easier to come by.
-Tacky, rambling a bit...