Nice idea.. tho i do not think Anet will make weapons compatible by equipping it in another set. Pretty sure duel handed will always remain duel handed, main as main and offhand as offhand. Tho i do see possibilities in spear and trident becoming a territorial weapon.
That being said guardian does already have access to frequent burning. Adding a condi spec specialization will bring serious balance issues to guardian. Maybe not in Pve, but i can definitely see it happening in PvP and WvW.
I’m not sure about the first part in terms of weapons, given how many expansions there will be I’m not sure if just the aquatics becoming territorial would provide a lot of diverse play. Adding trident for example on Mesmer would basically just be another staff. Throughout the years I’ve seen Anet try different things to see if they would work and I think the offhand weapons in the main hand have a lot of potential for dynamic play and add a new level of diversity for the game.
In regards to the second comment, I can see this being an issue in PvP and WvW. But as we’ve seen in recent updates Anet has been balancing class skills for specific modes, I’m sure they can tone down it’s damage and balance in such a way that can make it viable but not too strong in PvP/WvW (i.e. tuning down burn damage given by specialization).
