Someone earlier mentioned shooting to the body and only finishing with a headshot - is this true even for DMR? I usually go only for the headshot and inevitably I will miss at least one of those per encounter. Should I be aiming for body first, or maybe try another weapon?
You do the same damage to their shields on the body as the head, so always go for the body first to lower their shields and pop them with a head shot to finish the kill quickly.
Someone also mentioned sticking close to walls and not running out into open spaces. I can understand why I shouldn't be running into open spaces, but if I stick close to walls will I not be easier to kill with grenades?
I wouldn't say necessarily stick close to walls, but you should try and move from cover to cover rather than running through big open spaces to get from point a to point b.
Speaking of grenades, when is it best to use them? Should I use them at start of a fight? At end to finish them off? Or only use them to throw around corners?
I use nades in both contexts. Either when you see a dot on your radar around a corner, drop one to lower their shields or at the end of a battle as a last ditch effort to kill your opponent. Dropping nades right before you die is often a good way to clean up the guy who killed you as well, since you wont get those nades back anyway.
Any other tips that will help me? I really love the game and know I'm probably not going to be a 'pro' but would like it at least finish my games having not completely dragged my other team mates down.
I think the biggest one is DON'T chase kills. It often feels like the right thing to do, you pop a guy's shields, he's one shot and you want to finish him as he runs away. Likelihood is, unless he is in a fairly open area, he will have a backup plan to take you down. He could have a shotgun, he could drop a nice nade as you round the corner he just turned or more likely than anything else, he will run you into a 2v1 situation and you will die. Let the kill go unless you know you can definitely finish it.
Also, just a basic tip: As a general rule, keep an all rounder weapon with you. Don't swap out your DMR/BR and roll with 2 power weapons just because they are good guns. The primary weapons are designed to be all-purpose, whereas power weapons are for specific situations. There are exceptions to this rule obviously, rockets and sniper or shotgun and sniper can be pretty effective if you are camping a location, but I would generally steer clear of it. Even if you are T2...
Lastly. If I'm now getting matched up with people above my skill level (didn't have this problem first few days and was kicking butt) will the game recognise this soon and start matching me with other people that are more at my level?
According to 343 the game uses 'trueskill' in the background to match you up with people of a similar skill. This means if you consistantly win games, the game will match you with people of a higher skill level until you start to have a more consistant win/loss ratio or 'level out'. Same goes for if you lose games, you should start to play lower level folks that match your skill level.
As a general comment, I just finished my Solo Legendary run and really enjoyed it, the cutscenes had more impact and the gameplay was fanatastic. Not especially hard, died maybe once or twice per level, but much better than the hideously easy Halo 3 and Reach campaigns on Legendary. I recommend everyone play the campaign Solo Legendary, I got a lot more enjoyment out of it than my first run through.