I like some of the sounds you are getting but to me the issue seems to mostly be with the guitars. In the drum+bass+guit clip the guitars are way too loud and the high mids/highs are completely dominating. When you have something sticking out that much its impossible to sound glued. You're doing something I do alot too though, and everyone does to some extent. You don't have the whole song down yet so you're trying to make it sound like a whole production when there isn't one there. Try to mix knowing that other things will need to be in there. Those guitars will kill vocals and everything else too. I have a habit of making guitars too bright sometimes too, but when I do it the whole track suffers. Also be careful of the volume of any one instrument. Remember they are working together to create a bigger picture. For instance, if you want those guitars to sound big and punchy then you have to let the kick and bass do their job. They will emphasize what the guitar is doing if the guitar isn't completely covering them. Also be very mindful of the performance. When things arent locking up you immediately kill impact. In the beginning chuggy part everything is a little off from everything else in places which will cause problems you can't fix with any EQ or compressor. Notice in the second part of the clip everything starts gel'ing better because everything is more locked in.
Now on to more specifics. Just for shits I did a 10 min mix of your raw tracks to try to bring down some of the things that were bothering me so I could be a little more specific. I also tried to take into account what you might be going for since you definitely accentuated things. Resist the urge to make your guitars sound like a razorblade. You can't solo guitars when you EQ unless there is just something terrible in there you need to find to remove. In the case of your clip 2k and up was just chainsawing me so I used a shelf EQ to bring down a bunch of that starting around 2k. I also took a generous scoop out of 500-800Hz. It made the guitars a little less cluttered so your bass could be heard a little better. The lowend was also pretty thin but a lot of that was also because the mid-high end was boosted a lot. I think its good you are HPing things but when doing them make sure to listen with your other tracks going so you can hear when you've thinned it out too much. If you have to take them that far because the lowend is already there but it sounds off then you have to look at what istaking up that space that your guitars want to be in. So I boosted a bit down low until I could hear it starting to mesh with the bass more. Overall wanted to try to keep the character of your guitars intact since you obviously chose that sound because you liked it but also make room for some other things.
Onto the bass. It sounds cool by itself but you have to figure out what role you want it to have in the song. Is it just there to support the stuff on top of it? Are you aiming to actually be able to hear it or just feel it making the guitars bigger? If you want it to be heard but not completely clobber the guitars room you'll have to thin it out a good bit between 250Hz-1k. Again its about listening to it in the context of the mix and not by itself. I'll admit it sounded cool by itself but as soon as you put the guitars in there they are fighting and then it becomes and issue of whether to EQ or if something is just too loud. In this case I felt it to be an EQ issue. There's plenty of room for everything but not if you have everything going balls out all over the place. In the little mix I made everything is still overblown and needs more control in my opinion but I made everything super loud so you could at least hear it all punching through. So for the bass I cut the mids a good bit. It didn't sound as full alone as your original track and but it made it possible to bring it up in the mix without killing the drums or guitars completely so you could actually hear it more if that's what you wanted. So I left the lowend alone, cut some mids and brought it back up around 1k-3k so you could hear a little of that rattle. So again it comes down to what role you want it to play. Is it there to be felt? Heard? Character? I chose to have it hold down the lowend, be heard and and while it still has plenty of mids it leaves room for the guitars. On the drum track I just did a little cut between 4-5k to bring your kick click down a little since I was killing the highend on everything else and the click was sticking out a little more than I liked.
What really helped me start to get better though was asking myself what I was trying to do overall and what I wanted certain instruments role to be. Works out much better than trying to get everything to sound badass alone and then cramming it together or cutting or boosting just because you read it somewhere. Remember those things you read are good to know only if you know why you are doing them. If someone says to do a big cut between 200-400Hz understand why you're doing it and what you're combating so you know when to do it or when to leave it alone. That and when you encounter a problem you're more likely to have an idea what needs to be done instead of just randomly turning knobs hoping it gets better. Also try mixing into a bus compressor. I try not to take off more than 4dB at the loudest point. It'll be more glued and hit harder if I go farther but it also starts sounding smaller so that seems to be a sweet spot for a lot of people in regards to bus compression.
I know this is long winded and I repeated myself a lot but I think understanding the concepts are important if you want to improve. I'm constantly still struggling but by having this mindset I'm finding that I struggle less and I'm sure as time goes on I'll get better and better. I'm actually doing preproduction with a band right now where I have the same kind of situation. They want it to sound raw, but modern, have a big nasty bass, and big guitars. So the battle rages on.
Anyway this mix is not great by any means but it's the best I can do in 10 mins!
Everything is loud and hopefully it'll give you some ideas.
2nd clip is the preproduction I'm working on where I'm dealing with a similar instrument situation. Static mix (no automation) and everything was EQd for the middle part so FX are a little too much in the beginning but I like them in the mix. Take it easy dude! Good luck!
Your clip -
http://dl.dropbox.com/u/8643460/exmeh.mp3
My prepro -
http://soundcloud.com/mesa4x12er/roughy
