If you worried about burning the carto grab some horizontal cartos, the coil doesnt touch the filler so they wont burn. You will get a kinda burnt taste when carto is out of juice but thats fine just means to fill up again, its just dry hitting thats all and, you wont hurt the carto at all. The ones I got from nhaler I have filled ten times, and still performing like when I first got em. Also for TH try str8pg or just 75pg/25vg will work great like some people b4 mentioned, and yes the nic level matter some, and some flavors hit alot harder than others like coffee flavors for instance. If you like tobacco flavors, I found a nice one called casablanca from backwoods brew I love, needs to steep a couple of weeks to bring out full richness. And also vapor4life has a huge assortment of nobacco prem juice which is str8 pg, and I have gotten some flavors there and most all tasted spot on, peanut butter cup is the new one I got, and it has a mellow peanut butter taste like a reese cup when you exhale its great. Like you I also spent a lot of loot not finding the right flavors though, even ones people raved about and this is because we are all diff. Most the flavors from good companies might taste and smell spot on but you wont like the vape. Because things we eat that we love, we wont always love when we vape, so it can be hard to find the right flavors out there. But dont give up. Cause once you find your few you love your good. Hit me up if need any info. 
