Are there any practical uses for a light power rod in bass fishing? Would it be practical for use as an everyday finesse setup?

I think it should work fine.  Before I got a Light rod, I used my Ultralight for fishing a wacky-rigged senko on a regular basis.  I caught 3 or 4 over 5 lbs in one summer on the UL, but  lost some good ones too.  That's why I moved to Light.

Yes, any technique that falls into the rods weight range. Just remember that the listed power doesn't have a set standard. So one companies light could fish like a medium light or vice versa.  A buddy has a medium Powell diesel spinning rod and it's very stiff. It's stiffer than some of my MH casting rods. 

For me yes there is!
Sorry this got quite windy!
10-15 years ago had a hand, wrist injury and the heavy spinning rods with light Texas rigs and mono was killing me. I fish mostly outside weed lines or deep Lilly pads and some can get quite thick but not much matting.  Switched over to 6’ ML rods with 10# power pro and I felt my catch success really didn’t change or maybe improved with better hook sets because of line stretch. Just joined this forum looking for advice on lighter casting rods. Planning on building a medium light casting rod and didn’t know if I was crazy or not? Been surfing a lot of forums lately and most people use heavy rods and heavy braided line. I would like a light rod with 10# (weight not diameter) braided line to throw Texas rigged plastics that weigh ¼ to ½ oz. total. Not worried about setting the hook, with a fast tip it’ll bury the hook without much effort. I’ve been playing with Abu Garcia 4600 reel on my ladies 6’6” medium Rainshadow blank and seems way more than stiff enough and casts quite well with senko type baits. Does anybody else fish light setups like this?

I used a L StCroix Premier as my main rod for the first year or so of bass fishing.  Now that I have a wider rod assortment I can see where I am missing hookups fishing say a weedless Ned on my L rod vs the ML rod I now use.  

But in general I did pretty decently with it and still use it for openhook baits when river and stream fishing.  

Depends on the waters you fish. For me, when fishing clear, open waters, I absolutely have a dedicated L action rod for 5 and 6lb fluoro. I throw light hair jigs and plastics (4" worms and 3" grubs) and it works better than my ML setup. I use 7lb on my DS rig (ML) and 8lb on my 'all-around' spin rig (Med).

Of course there´s room for L and UL power rods in bass fishing, the catch is to detrmine where and when:

Most definately NOT here ! :

Here, you can bet YES ! :

Neg rig fishes nicely on light power rods.  I use a 7 foot 2 inch walleye jigging rod with the ned and it works very well.  In open water and with light lures/light wire hooks like the ned, the rod is  forgiving, casts well, but will handle good-sized fish just fine.  I suggest longer rather than shorter lights and ultra-lights to help with hook sets.  I used to use 6 foot UL rods and lost way too many fish to poor hook sets.