It's just not a good idea to do melee/ranged hybrids. Ranged is superior to melee and you'll very rarely have a reason to whack something when you can shoot it. You play melee because its more fun and challenging. Sure, when using LMGs youll want to whack a weak or wounded enemy in melee instead of wasting a burst, but thats pretty much it.
Sword builds arent good for exploration because you can't afford the per for secrets and detection, though you can have good str/dex/agi for those checks. If you invest (specced snooping, paranoia, detection goggles, balor tattoo, drugs, etc) you can do alright but you wont be able to out-do deathstalkers or lurker snipers and things like that until the lategame if ever, but that's going to lower your sword effectiveness by a bit.
So I suggest doing a focused ranged build and then a focused sword build; if you like the game you'll replay it anyway.
Flurry is the bread and butter of sword builds, and you always take onslaught. Decapitate is worthy on strength sword builds. Ripper is overkill; in my experience it makes it harder to get flurry built up which is bad. Parry and riposte are bad.