Taking on the boys in green

So, I've been playing a friend in our club and he has beaten me every time for the past few months due to playing Salamanders using drop pods with sternguard with combi-meltas and a chapter master death star, usually blowing up half my tanks and claiming/denying objectives with the chapter master. Now, admittedly, most of this is probably my fault (I am both unlucky and indesicive in most games).

Recently he has started playing 30k salamanders using their rite of war which forbids drop pods. Sounded like a godsend but now he uses 3++ firedrakes with Praetorian or Vulkan in a land raider and pyroclasts and tac marines in rhinos. the rhinos i can deal with, but I would like to know any thoughts how to stop a death star like that with a primarch at the head, especially in capture the relic where he snaches the objective turn 1 (like he did to me recently)

Also did i mention all the fire?

Okay...well, first off, Vulkan costs over 400 points, and with a land raider that's like 600+ points right there.

So, my initial question is - what point level are you playing?
My second question is - can you tell me what you are choosing to field, because often I see newer DE players making poor decisions when it comes to fielding a high number of points with DE.

As far as dealing with 3++ Marines?
Shoot them with poison. We don't care that they're 3++, they will die to poison shots just as easily as a 3+ Marine. Use your blasters and lances to bust up vehicles and then spray down the occupants with poison. Wracks are also quite solid, as they'll chop them up just as well as anything else.

Vulkan...well, all the primarchs are pretty ridiculous and he's really no exception though he's hardly the worst amongst them.
Again - poison is your friend. It will negate his toughness and, functionally, make him no harder to kill than a squad of Terminators, because his toughness won't matter. Basically shooting him to death is your best option as there is very little in our codex that would want to get into a brawl with him (and anything that theoretically could, would be better served killing mobs of other mooks while you shoot up Vulkan).

I would tend to advise shoot his transport out from under him and pour fire into him. Or, focus on the rest of the army and use your mobility to hamper how much he can kill, and worry about him after you've gutted everything else. But you definitely should be trying to kill him with shooting, not assault.

Kill Him with mosquito bites.... make him roll 50 saves a turn..... only way to kill those guys... honestly I would probably go 'REALLY, you are going to run a PRIMARCH against me?'...if a friend, ok we can playtest, if not a friend I would give stink eye and use every dirty trick in the book and there has been quite some discussion on 30K vs 40K ...SOME of the armies balance ok, some not so much.

SEE this the the PERFECT reason for GW NOT to get rid of characters... you run the Duke(?) and then all the splinter stuff becomes 3+ poison instead of 4+... HUUUUUGE difference in wounding capability..... Hell, take him anyway as a 2nd HQ,get the upgrade and THEN see how it goes when wounding on 3+ regardless of toughness.... he wants to play uber... good luck with that...oh I agree, take out the land raider asap, make him walk....

last thing, watch out for some LR fluffy stupid stuff like there is some kind of LR that actually has equivilent of 'it will not die' or 'eternal warrior' YUP WTFH!? is right.....

the games we play tend to be 2000 points, so Vulkan with with squad and land raider come at over half his points i think. i usually field 2 squads of blasterborn and slicsus with shardborn and 2 squads of warriors. after that, i go for wyches and/or reavers and whatever else i can fit in for the points (normally i like Razorwings but against this guy, i would probably use ravagers).

I know 3++ Marines should be easy to kill but firdrakes are just insane, they are basically GK paladins with storm shields, so he tends to Look-Out sir! my poison and takes the blaster shots on Vulkan if he can.

Duke is amazing. I always use him when i can. dropping 2 blasterborn venoms and Duke's squad behind your opponents army is priceless you can pull it off (which i sadly don't do often).

Personally I think playing 30k Marines Vs. a non-top-tier army such as ours and then topping it off by running a Primarch is a real dick move, but good luck to you if you think it's acceptable. I just feel that the best piece of advice I could give you to make your games closer is to tell you to ask your friend not to be so harsh. I've heard lots of differing opinions on the subject regarding relative power-levels between 30k and 40k and, to me, they're all pretty much moot; they aren't meant to be played against each other and therein lies the (potential) problem.

one tactic I think might help is to deep stick a large chunk of your army AFTER he brings in his drop pods, Make sure you wychs and kabalites are mounted in raiders, Shadow Field should help you out range those meltas, Just keep moving away and poking at them.
Another good thing to use against his death star are disintegrater cannons, Nothing like a wave of ap2 shots to make him take invuls. With most of your kabalites mounted with splinter racks you will have plenty of shot and re-rolls to sting most of the stuff to death.
Your major advantage however is he does not have many units to shoot with. So in hind sight give him a lot of targets. At 2k points I see no reason not to have 6 raiders with flicker, shadow, racks. mounted by kabs and wychs. plus all of your other goodies. if you unmount them then you just double your targets.
Oh and dont for get my favorite anti marine. The Chronus. Nothing like ap3 templates to just brighten there day.

These are not tactics together just a bunch of different ones listed.

Surround his LR with Hwyches and then wreck it. Rocks fall, everybody dies.