[S/M] Questions about EV Training

[umbagog]

Hey all,

I'm fairly new to the new generation (haven't played since Silver/Gold) and had a few questions about EV training in Sun/Moon:

1) I read on Serebii here that when you chain SOS pokemon, you can get double the number of EV points so you can potentially max out a specific EV within 7 pokemon if you have a Power Item and PokeRus. My question is whether the doubling effect applies to the original mon that calls for help too. 

• For example, (assuming I have a Power Anklet for Speed and Pokerus) if I run into a Zubat and that Zubat calls another Zubat for help, would I get 36 EV Points in Speed (((1+8)*2)*2) for beating the helper Zubat and 18 EV Points in Speed ((1+8)*2) for beating the original Zubat? Or would I get 36 EV Points in Speed for defeating the first Zubat and another 36 Points for defeating the second Zubat?
  

2) When you max out a particular EV stat like Speed, but you have not yet maxed out your total available EV points in other stats, can you "waste" EV Points by accidentally defeating mons that give Speed EV Points?  

• For example, assume that I have a Zubat with 252 EV Points in Speed (that's the max, right?) and no other EV Points in any other stat. If my Zubat then defeats a wild Zubat, will it "waste" an EV point that I could otherwise spend on a stat like Attack? 
  
• Put another way, if my Zubat has 252 EV Points in Speed, and has 258 (510-252) remaining EV Points to spend, will defeating a wild Zubat lower my Zubat's available EV Points to 257 (509-252)?
  

3) How do you get PokeRus in S/M?

Thank you!! Sorry for the long-windedness but it's been a while since I've done this and I want to get back into competitive play!
Umba