I'm generating spirit by just... attacking I guess? I really rarely feel like I'm low on spirit. I can't have my mantra on double time 100% of the time, but really it's on quite a bit. I'm attacking pretty slowly, too. I actually ditched most of my attack speed stuff recently for crit chance stuff, too, but I'm running with Thunderclap so I don't get extra spirit from crits or anything. I don't use any big spirit thing except sweeping wind. And yeah I run into some times where I have to wait a few seconds to turn it on, but once I get a combo going with it, everything's fine.
I was running a lot of the same skills you were. I had Evasion with Hard Target and I was running lightning flash before I made the switch. I wasn't dual wielding though, since it always seemed to hinder me way more than it was worth. I'd switch to try and it out and get beat to crap even with insane LOH values (one time I think I had over 2000). Probably just had bad luck, though. Anyway, when I switched to conviction with sweeping wind (cyclone) things clicked while soloing. I had to be a bit more careful about spike damage while fighting elites, but I could power through almost anything in Act 3 and 4. Way faster than before. And when I got to an elite I could burst them down a lot better.
Personally I think you should switch guardian's path for resolve. I've not seen anyone that seriously looked at the skills in they game and figured out what's best that ever recommended Guardian's Path. For damage mitigation Resolve is where it's at.
And yeah I hear you about switching to more DPS. That's what I did recently and it's way way more fun. As I said, I was running pure tank with evasion and stuff before. Yeah I could hang with anything, but now with conviction and cyclones everywhere my groups (and solo) can just annihilate things that I had trouble with before. The game's completely different and I'm having a ton of fun with it. Cyclone takes a large amount of crit chance to be worth it, though, and dual wielding it's hard to get there (my shield alone gives me 9 crit chance).