i've started also as DB RK player (and still im using it for farming/hunting)
Top Headgear: Rideword Hat (Leech); Rocket Helm (fast movement - i love this helm)
Mid Headgear: Robo Eye or New Wave Sunglasses
Lower Headgear: Umbala Spirit or Well-Chewed Pencil
Armor: Glorious Suit (max hp=more damage)
Weapon: Thanatos Greatsword (with hunterfly card and enchant it and of course for Parrying)
Garment: any GSS as long there is Vit/Dex or pure vit
Shoes: Temporal Boots of Dexterity with EA/ME (at least there is EA) (first priority so that you can cast DB fast)
Accessories: Sheriff's Left Badge (good starter); Ur's Seal (with HP or SP enchant); Expert Ring with EoE Vit 3 (for ACD) or Sarah's Earrings (as long there is EA or Delay After Cast)
Dont forget to have Incubus Pet for SP Leeching.
for your guide on your question:
1) Solo Leveling is ok but it will takes time to gain your experience. i prefer to join party in Gramps and do as semi tanker (Parrying helps you on this for luring)
2) Farming Areas: starter: Gonryun Dungeon (Royal Jelly); Mid-Farming: Juperos/Magma Dungeon (all loots sell it earn 1-2m in 15-20mins); High-Farming: Geffenia
3) Illusion Goibne's Set will give ACD, Resists and high hp which need by DB RK.