I think you did a pretty good job for an in-game team! You matched each Pokemon's best stat with the best type of move for them. Which from my experience and my own opinion is one of the best ways to start.
Houndoom looks pretty good. He's a high special attacker and you matched him up with special moves. My only suggestion is possibly taking out Fire Blast. I find that sometimes it's better to go with lower powered moves for the pay off of having a better accuracy. Fire Blast may be a strong move, but it's inaccuracy can really hinder it. That's why I'd stick with Flamethrower. It's still powerful, it's still a fire type attack, but has 100% accuracy. You could replace Fire Blast with Sludge Bomb which only is super effective against grass types, but it does carry the side effect of maybe poisoning your foe. If you're not big on Sludge Bomb then I'd also suggest Embargo. I'm not a big status move person, but Embargo is an exception. Its effect of keeping your foe from using an item can really come in handy once you face the Elite Four.
Lapras looks good also, but my concern is only having it know two types of moves. As I said before you may want to go with lower powered moves that have a high accuracy over high powered moves that have a lower accuracy. In this case keep Ice Beam and Surf. Both are accurate and have a good base power. I'm once again leaning towards a status move like Confuse Ray. It has a 100% accuracy of confusing your foe which is great for you! Some other moves you could teach it in place of Blizzard and Hydro Pump are Thunderbolt, Psychic, and Dragon Pulse.
Keep Earthquake on Donphan that's the best move you have going for it right now. Also I like your idea of teaching it Poison Jab. I can see where that would be great if you're up against a grass type. I'm not a big fan of Iron Tail. Its inaccuracy is extremely annoying and you can't always afford to miss. May I suggest possibly raising your Donphan to level 54 where it will learn Giga Impact. It's the equivalent of Hyper Beam except Giga Impact is for high attack stat Pokemon like Donphan. Toxic is kind of up in the air. You could really use it if you want, but you do have Poison Jab which gives you the possibility of poisoning your opponent. My only other thought is possibly teaching it Attract instead. That is only if your Donphan is a female. Seeing as I tend to notice a a lot more male opponents then females.
With Dragonite I would choose Thunderpunch over Thunderbolt. Dragonite has a higher attack then special attack making Thunderpunch a bit more useful. I'd even drop Focus Blast and go for Brick Break if you're looking for a fighting move. I personally am a little more for Outrage then Dragon Claw even if it does cause confusion, but that is totally up to you. Another thought I'd like to throw out there is that you could also teach it Roost. After using Roost Dragonite's flying type is canceled out only make it a Dragon type. (Only for that turn.) Therefore if an opponent uses an Ice or Rock type move they won't be as effective while you also get the benefit of restoring some health.
Lugia being a legendary means you really don't have to go out of your way to ensure it a hard hitter. If you really want me to go over Lugia then you can just vm me or post within this thread, but I think you'll be fine.
For Tyranitar keep Crunch. Shadow Claw adds something different to its move-pool so that's fine to keep too. Stone Edge is fine, but as I've said before I'd prefer Rock Slide over it for the better accuracy, but honestly in this case it's not that big of a deal. Lastly if you're teaching Dragonite Brick Break then you probably don't want Tyranitar to have Brick Break also. You could use a Heart Scale to teach it one of the Fang moves. Fire Fang would be great for when it encounters grass or steel types and Thunder Fang is great for encountering water types.
