Ok, a ton of questions in a row with no answers. Let's see if I can't clean this up a bit.
A Speed Boost Yanmega may trick the Heatran player and pick up a kill. Against ScarfTran, you come in after a kill and Protect, netting you the boost so you outspeed. Then fire off a Hidden Power Ground for a possible OHKO. Against LO Heatran, you can switch in to a predicted Earth Power and do the same. A good player won't stay in, though, so you will need to play carefully.
Wi-fi Ubers isn't that popular, so you will just want to go with something that appeals to you/is fun to play. The Dual Screen lead is quite solid and will let you potentially get creative with the rest of your team, since it is such a great team player. I would not fool with Shadow Ball on the suicide lead; it just doesn't do enough there.
It is hard to answer this question without knowing whether you mean a Block trapper or a Pursuit trapper. They are very different. For Pursuit, you are probably best off going with the Choice Band set from the analysis with Pursuit in place of one of the attacks (since you will need Banded max attack to get a decent punch out of unSTAB Pursuit).
If you mean Block, that's an odd set. It will really depend on what you expect it to counter. I'd need more information to tell you anything useful.
This team is very physically based right now. It could also use a good Ice user to take down things like Cynthia's Garchomp and Bertha's Gliscor and Hippowdon. A Milotic could solve both of these problems with its huge special bulk and powerful Ice Beam. A Weavile would also be a good inclusion, able to contribute with both STABs, since the Dark is excellent against Lucian. Weavile can even outspeed his Alakazam!
Blastoise is a good Rapid Spinner for you, as it is quite bulky and can learn a number of useful support moves, such as Yawn (you currently have no sleep and only one phazer). As for your revenge killer needs, a SubCM Mismagius is quite fast, packs a whallop, and can even help you stall a bit with passable (and boostable) special bulk, Substitute, and more reliable spin blocking than Froslass.
I would advise against trying this team in OU. Nearly everyone on the team has much bulkier equivalents in OU who have a hard enough time stalling against potent OU threats as it is. I mean, Dragonite is treated as a sweeper, viable on hyper offense teams, and it is significantly bulkier than Clefable or Nidoqueen. That should tell you something right there. Keep it to UU unless you want to switch some of your guys out for Forretress, Blissey, etc. (i.e., make the team much less interesting).
Can someone here help me to think of a effective lure for Heatran, especially Scarftran? I'm trying to set up a sweep for... something... and I need Heatran specifically out of the way. Any ideas?
(I tried Dugtrio a lot, IMO just not a good pokemon in OU. Just doesn't cut it nowadays...)
A Speed Boost Yanmega may trick the Heatran player and pick up a kill. Against ScarfTran, you come in after a kill and Protect, netting you the boost so you outspeed. Then fire off a Hidden Power Ground for a possible OHKO. Against LO Heatran, you can switch in to a predicted Earth Power and do the same. A good player won't stay in, though, so you will need to play carefully.
How should I EV my Deoxys? It's Timid so it can't use Extremespeed. So now I'm stuck between using the regular lead set with Shadow Ball over X-Speed, or the Dual Screen lead. But I don't know if Shadow Ball is worth it. What should I do with my Deoxys?
Wi-fi Ubers isn't that popular, so you will just want to go with something that appeals to you/is fun to play. The Dual Screen lead is quite solid and will let you potentially get creative with the rest of your team, since it is such a great team player. I would not fool with Shadow Ball on the suicide lead; it just doesn't do enough there.
What is the best ev spread for a specially-defensive trapper Metagross?
It is hard to answer this question without knowing whether you mean a Block trapper or a Pursuit trapper. They are very different. For Pursuit, you are probably best off going with the Choice Band set from the analysis with Pursuit in place of one of the attacks (since you will need Banded max attack to get a decent punch out of unSTAB Pursuit).
If you mean Block, that's an odd set. It will really depend on what you expect it to counter. I'd need more information to tell you anything useful.
what else should I have for this E4 team?
Infernape
Staraptor
Luxray
Gyarados
This team is very physically based right now. It could also use a good Ice user to take down things like Cynthia's Garchomp and Bertha's Gliscor and Hippowdon. A Milotic could solve both of these problems with its huge special bulk and powerful Ice Beam. A Weavile would also be a good inclusion, able to contribute with both STABs, since the Dark is excellent against Lucian. Weavile can even outspeed his Alakazam!
Froslass: Spikes/Ice Beam/Shadow Ball/ Destiny Bond
Milotic: Surf/Toxic/Rest/Sleep Talk
Clefable: Aromatherapy/Wish/Stealth Rock/ Seismic Toss
Nidoqueen: Toxic Spikes/Roar/Super Fang/Earthquake
Who should I use for the last two slots, and could this be an efficient stall team? I was thinking of having a Rapid Spinner and some sort of Revenge Killer that would be a last resort...
This is for a UU stall team but I wouldn't mind using in OU! So who deserves a spot in the final two?
Blastoise is a good Rapid Spinner for you, as it is quite bulky and can learn a number of useful support moves, such as Yawn (you currently have no sleep and only one phazer). As for your revenge killer needs, a SubCM Mismagius is quite fast, packs a whallop, and can even help you stall a bit with passable (and boostable) special bulk, Substitute, and more reliable spin blocking than Froslass.
I would advise against trying this team in OU. Nearly everyone on the team has much bulkier equivalents in OU who have a hard enough time stalling against potent OU threats as it is. I mean, Dragonite is treated as a sweeper, viable on hyper offense teams, and it is significantly bulkier than Clefable or Nidoqueen. That should tell you something right there. Keep it to UU unless you want to switch some of your guys out for Forretress, Blissey, etc. (i.e., make the team much less interesting).