[Joppa]

Yes. As a visa national, you need a UK visa or EEA family permit to travel to UK (airline won't let you board the plane without). It's best to wait until you get your Permanent residence card before leaving UK.

 

[Joppa]

Currently EEA family permit is taking about 3 weeks in Nigeria.

 

[Joppa]

Not for EEA family permit, which is supposed to be expedited anyway (doesn't happen though).

 

[Joppa]

It's now called EEA dependant ink stamp. You can try but they are just as strict. Recently a large number of inadequately-documented travellers were stopped at Calais. You are unlikely to be allowed to take an Austrian hire car into UK, and even if you can, the drop-off charge will be astronomical.