Generally I stick with 70/30 for DL vaping, but if you don't find 50/50 too harsh to vape at higher wattages (and it doesn't leak) there is no reason you shouldn't. Higher PG gives a 'throat hit' so generally 50/50 juices are vaped at low MTL settings as you may find it a bit harsh on the throat at higher settings because you are vaporising much larger amounts of liquid with each hit. My advise is suck it and see - if you get a sore throat from the higher PG ratio then obviously it's a NO. 50/50 is much thinner than 70/30 juice and may oversaturate the coil and end up flooding it out, if this happens then again it's a NO.
I think the reason you aren't particularly impressed with the flavour will be down to one of two reasons -
1. Regular 10ml 50/50 juices that come ready to vape with nic already added are formulated to be vaped in tiny amounts at lower power settings, because of this they are more intensely flavoured. Larger shortfill bottles that you add nic to are designed to be blasted through in a DL tank at higher power levels and don't have the higher ratio of flavouring that the smaller pre-nic'd MTL juices so some DL juices can be underwhelming at lower power..
2. You have bought a mediocre shortfill and the manufacturer has scrimped on the flavourings (flavours are the most expensive ingredient). There are a LOT of juice manufacturers out there and not all of them are good. Sadly finding juices that hit the spot can be the most frustrating part of vaping and it can take a while until you find out exactly what works for you. Unfortunately it is often a case of you only get what you pay for, when I've gambled on buying juice that was cheap generally it hasn't ended well and the bottles I actually managed to vape I can't say I particularly enjoyed.
If you mention your flavour profile preferences (fruits/sodas/deserts etc), if you like/detest ice or menthol and if you're looking for MTL or DTL juices you will get plenty of suggestions on here that will cut down the Russian Roulette factor of buying mystery brands.