a) you can watch his youtube series about grim dawn guides and the “grim dawn” playlist to see his level builds etc… https://www.youtube.com/user/Malaganted/playlists its IMO one of the best youtube contet creator for grim dawn with realistic guides and builds.
b) to rush smooth to the game is more or less for all classes the same:
- take one skill to build around, example for a 2hand physical dmg char. Forcewave. Max it. and get everything that helps this skill. In this example. Physical dmg, physical resistance reduction, cast speed, offensive ability, big weapon with high dmg range
- take some stuff that helps you to stay alive, skill wise, heal spells, absorb shields, defensive ability, reduce target dmg skills etc…
- A LOT of your char power comes from gear. In the levelphase too. So you need to take care of this: 3.1. try to max all resistance, 3.2. get high physical resistance and high armor and high armor absorption 3.3. if you come from poe, poe players says: “grim dawn is easy, you can stack health and regen and you will be fine”. So stack Health and some heal devotions like chariot, behemoth and/or the harp
if you come from poe you should know what you are need to look for on every gear slot:
double or triple resistance rolls and health plus your dmg typ roll (physical), offensive or defensive ability and armor plus all skills, or plus soldier/shaman are great too and later in the game needed to get more power
https://www.grimtools.com/calc/eVLPrdGV example for a char with good start gear. (taken from this guide https://www.grimdawn.com/forums/showthread.php?t=49754)
example for melee start builds for level 50 soldier 2hand https://www.grimtools.com/calc/pZrAYJ6V <- physical dmg shaman 2hand https://www.grimtools.com/calc/M2gEb7yZ <- Lightning dmg nightblade dual wield melee https://www.grimtools.com/calc/O2GXbKlV <- cold dmg and squishy
you see how this works. get one skill to work around, get the right devotions (resistance reduction for the dmg type and heal devotions) get the correct gear (health, resistance, plus skills, offensive and defensive abillity) and you are good to finish the game easy to start ultimate.