Like can I have on my hoplite a one hand spear+shield+a subweapon in another slot? or do I have to take my shield off and put the dagger in my shield hand to get the fire attribute damage added to my spear attacks?
The only videos I can find are 2-3 years old so it may have changed by now.
no, your shield and sub weapons take the same slot…
you have 2 hands…
BUT WAIT! LEATHER STRAPS! can’t i just mount extra weapons all over my body?
that’s the worst idea ever D:
one thing is having them safely put on you bottomless pocket, but having them around you is a health hazard 
lol, well thats fine. when soloing or dpsing on my hoplite, the dmg increase from arde dagger in offhand more than offsets the lack of a shield. Hell with the arde dagger, my auto attacks with my main weapon will hit for more than my skills that require a shield to use do. Unless said mob is weak to strike anyway, but in that case I’d use a mace in main hand, I carry all 3 damage types with me, but I only upgrade the spear since its my main weapon. That 50%+ damage boost for using what physical damage the mob is weak to is massive, like I can go from hitting for 300 with piercing to hitting for 650 per auto attack by just switching to a blunt/mace. Combine this with arde dagger, and yeah… thats 800(to 1000 dmg a swing if they also weak to fire) with just auto attacks. since arde daggers elemental damage effects your main weapon attacks too as a extra damage hit, kinda like sacriment from priest how it pops up that extra number.