same way you deal with the direct hit
Not really. The direct hit has bugger all splash damage, you can practically walk over the rockets.
It's a little hard to do because you get countered by all the noobs, but many soldier's wont expect you to do stupid shit like walk around in unthought out ways; purposefully moving around like an idiot.
Using rockets is almost like a tiny game of chess. You anticipate your enemies movements and then your enemy tries to counter anticipate you. Do you place your rockets at their feet incase they charge you, infront of them incase they keep strafing or behind if they change direction.
Most soldier's wont expect you to charge them head on (unless you clearly have your melee out) because it's the most dangerous thing to do; it's one of the reasons i also hate playing against bots. Their movement is so unnatural they're harder to predict as they don't have fear or desire so they wont retreat to health, protect themselves with cover or suicide for objectives.
The weakness of the LL is that it has fewer rockets, so firing just one puts him at a disadvantage. Ironicly, players who use weapons like the LL and BB prefer to spam their first rocket and reload hoping to negate the reduced clip size but it actually puts them in an even weaker position (with just 2 loaded rockets if they're ambushed). If you're a soldier, rocket jump onto them to avoid splash damage as his rockets will probably reach you first, knock you about and cause your subsequent rockets to be off target. If you're an engi use a mini-sentry, the reduced rocket clip size means you have an additional rocket reload over him destroying both you and your sentry. If you're a demo go demoknight, he's more vulnerable at close range; splash damage, your shield and his reduced capacity to lay down burst damage on you is a real advantage.
I shouldn't have to say anything about the HW guy as unless he's at point blank range and does 100+ damage with each shot he wont kill you with only his LL. Just makes sure you're walk at him if he's close enough so he takes some of his own slpash damage, the additional 30 odd damage a rocket really works in your favour as you also lay down close range mini-gun fire. The extra chips of damage against his health will often mean the difference between you surviving with 10 health or him surviving with 10 health.