The ghosting screen isn't software related as if I send someone a screenshot they don't see it.
So out of all the issues I have the only ones that can be fixed with a reset would be the speed and battery but the battery was bad out of the box anyway.
The fact that I cannot use my Bluetooth headphones with this phone without the wifi dropping, my broken microphone meaning I have to use loudspeaker to talk on the phone as well as the headphone jack no longer working properly even the charging port is starting to go loose.
Meanwhile the headphone jacks and charging port on my 4 year old dualshock 4 that I use daily works fine so I cant see how that could be me, plus the fact the OS is from 2016 and we're over halfway through 2018 gives me no faith in LG at all.
The bluetooth / wifi issue you're having could be coming from software too as they might be interupting each other somehow... Bluetooth and Wifi would use separate antenna's in that phone though, there is a chance one of them might have become lose from the MoBo of the phone and be touching the other antenna inside, if you happened to drop the phone really (almost to the point of breaking it) hard on the ground one of these might have slipped off where it should be, the ifixit review of the device is an 8/10 for being able to get into it.
It does have wifi/bluetooth worked into a single chip but it would still be using different antennas from the top and bottom parts of this board pictured.
Also they go into the battery being a fairly easily replaceable part in this, if you would be interested in maybe swapping that out and seeing if that would solve that issue for you?
with just a quick check I think this is the right replacement one, you should double check model number to be sure with your own handset first just in case I'm wrong with the link, but...
talking about an extra 1550 Mah to your current battery, for 20quid gonna at least give you a few extra hours and let it last a full day of use if not more.
Why not check me out on youtube and help me on the way to 2k subs over at www.youtube.com/stormcloudlive