RemoteControl

Have zero miles on Emirates. Flying a family of 4 SFO-DXB-SFO on Economy Flex fare. Questions:

1) Does it make sense to earn on Emirates with the hope that we'll use it again within 3 years? Or should I take the hit and earn half the miles on Alaska?

2) Is there any possibility of earning miles on the onward trip, and using that to upgrade at least one seat to business or Economy Plus on the return journey? From what I can tell, there's no obvious way given the miles required, but I thought I'd ask in case there is a hack I'm missing or some other possible way to get an upgrade.

3) Is Economy Plus worth it for passengers who aren't tall or heavy?

Thanks in advance,