Mhy.... relations in rpg games are a sticky topic (pun intended) coz its actually hard to merge relationships with Saving the world theme. And unless you wanna go the Japanese dating sim route you wont make it extra deep
Still people fighting togeather and risking lives tend to kinda bond me thinks, friendships and whatnot. Also its a fact that women like strong hero types that, or dudes kinda fall for Strong Hero Women or Cute Hero Women coz they are like that, they are close and well... violence and fear of death always works like afrodisiac Besides go back to the schooldays- how many guys girls felt their knees buckle when they saw Her/Him walking down the hall smiling and whatnot. Just make it... well interesting, talking. Asking for opinion, a lot of talk is always good. I will propably get crucified for that but i will name a Imoen romance mod- it had some really cool lines in it. For example- Imoen asking the PC how does he feel and wouldnt he liked some help, coz everyone else says - Do that for me, Youre the hero, Save village, Kill Dragons... now take cash and get lost. And great hero turns suddenly to an gloryfied errant boy that has to stay in corner and awat further instructions.
Heh... it seems its impossible to implement anything besides- gief rep then sex, then nothing. Or noone seems to care