I'm not too familiar with DBO, assuming that was a typo and not some other spinoff I've ever never heard of xD
It looks good, though, but I can't really compare with my limited knowledge. In my opinion though, Dragon Ball Z was still GREAT until... I'd say around the Buu saga, for me. Really, the introduction of Super Saiyans was where it started to decline a little, with the solution to most problems becoming "unlock a new Super Saiyan level", but it didn't really go overboard with it for me until the Buu Saga, where it just started pulling things out its ass. That said, I still would consider the Buu Saga "enjoyable", if not "great". GT is where it just... I don't like to talk about GT.
As for whether or not a non-smut rp can last, I don't really see why it can't. I mean, that's not to say this rp OR the proposed super sentai ish thing, would be completely without hot smutty action. I just generally feel like, the hot smutty action is far more enjoyable once you've given time for the characters to grow and develop. Maybe I'm just a weirdo, but I find the banging to be a LOT more hawt when I understand WHY the characters are banging; what lead up to them banging, what their relationship is, what the emotions going into said banging are, etc.
I mean, sure, I can enjoy a wham bam thank you ma'am quicky rp as much as the next guy from time to time, but by and large I like to have some story behind the action, so to speak. When I say non-smutfest, I basically just mean, the characters probably won't be banging for like... at LEAST 5-10 pages in, depending on the size of the group and horniness of the characters.