FINALLY, just set my record straight. Only took years of attempts 
I’ve been attempting to do UVHM on 1 life using all level 50 gear. I achieved it but did use the odd other gun above 50, namely a 52 Hornet. But for the most part, including Hero’s Pass I did with 50. Many FFYL along the way but with a Slag Rubi and Cloud Kill, got me up every time thank god. Cloud Kill is god sent for that.
Mains: Bee Shield, Fire Pimpernel, Shock and Corrosive Sandhawks, Hornet, Slag Rubi and Explosive Badaboom. Had a Legendary Siren (lvl42) with CDR relic, lvl48 Slag Longbow Singularity or lvl49 Homing Quasar.
Finished on lvl55 (long way to max lol). Only story missions. Hero’s pass wasn’t so bad, but the Warrior almost did me in at the last minute. The nearest to death was top of the Buzzards Nest in Sawtooth when 2 Heavy Nomads came out at the same time…tough moment!! Sawtooth once again proved the hardest part as it’s just mayhem all the way through.
Even though the Slag Singularity was lvl48, it mainly acted as a save the moment or group enemy. Knocking enemy off their track to give you that short moment to get Phaselock back or reload etc. really does help. The Siren COM only had 4 points in each too. Wish i’d had a Corrosive Pimpernel though, and even an Unkempt Harold so i’m pretty chuffed that i made do with the Hornet mostly.
Saturn is easy with a Corrosive Sandhawk and Bee even so many levels under. I used a Shock Sandhawk against The Warrior and Badaboom against Jack - though i did use a llvl52 Tesla v Jack too help against the shield. I used a Slag Bitch against Bloodwing, was very good.
Now i can have fun and die lots levelling to 72 
Funny thing is, not 1 Legendary dropped on the run apart from The Warrior. The Loot Midgets were SOOO stingy!!
FINAL SKILL TREE: http://bl2skills.com/siren.html#430501500015000000004505510501
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