wow you have been having fun
get down to boots and buy a bottle of vg for 2 quid ish (dont cost as much as juice when you get it wrong)
then building the thing with less and less cotton still it starts leaking
when you know that you have an idea of how much you need in the juice wells
the gurgling is prob from over priming and juice dropping down the air channels,to avoid this i have the mod on low power and pulse it a few times when im applying juice as it help it soak in
lack of flavour can be down to a few things but to much cotton in the coil is prob main one
the juice needs space to wick so if the cotton is to tight anywhere no flavor sept for dry hit
the way your fitting the cotton looks right ,so its prob how much your using
coils themselves can last yonks with the right care
kanthal you can dry bur like a mofo and put the coils under running cold water to shock the poo off( dont press the power button when the coils are in the water lol)
stainless steel you can do a v gentle dry burn on but dont glow them
im not familiar with the bro chromb they all go on about lol but im sure someone will say best way to clean them
fused clapton wire is rather easy to work with when it hasnt been rolled the wrong way 1st
https://www.wireandstuff.co.uk/products/Parallel-Coil.html
just remember to dry fire and get to start glowing from the middle out before wicking and rewicking
it took me about 6 month to get the nack of the tfv8 rba and it can still bit me in the ass