Best way to start, farm and attack early game with a Norse god?

Hi, i'm a player since old times of 2002 but i always focused on campaigns and editor, but never on PvP or PvAI Random maps. Now, with Extended Edition, i'm starting with them in a serious way.

I love norse gods and their amazing units, so i ask some advices from more skilled players. What strategy to use early game with norse gods for farming well, defending myself and attacking enemies for getting favor and pressure them?

I know the main strenght of nordic empires is being really aggressive to enemies, because they have awesome offensive units and they get favor with fights, but they have bad city defs. (weak walls, weak towers etc.) and a really weak sustain, so, should i focus all on farming and doing pressure to enemies? And what human units are better to train for early game pressure?

Also, i have a "bonus" question about playing Loki: should i pick Forseti for sustain (Healing Spring, the only possible sustain for Loki units because we lack Valkyries) or Heimdall? I personally find Einherjars better than Trolls because they boost your army while trolls are just simple archers, but Healing Spring seems op, so i'm not sure about the choice to do.