I started
vaping with a Bloog one month ago. I was also having difficulty trying to figure out how to get it to hit like a cigarette. I felt like I was sucking my lungs out, the muscles in my neck actually hurt from sucking so hard. I was kinda disappointed with it, so much that I bought a GoGo one week into it. The GoGo is a manual battery and it was much easier to hit, but I didn't want to give up on the Bloogs so I kept trying with it. About a week after I bought the GoGo I put it down and now all I use is the Bloog. The key is slow steady drawls, like you're sucking soda through a straw, but you only want a sip of soda, not a mouthful. Sucking like you've got a milkshake is actually counter productive and you'll end up less satisfied.
As far as adding VG to a Bloog carto, that's probably not going to give you the experience you're looking for. You can order some blank cartos and fill your own with a mix of PG/VG juice. I find that an 80/20 PG/VG ratio works really well in the Bloog cartos. I was a pack and a half a day lights smoker and I chain vape 6mg juice. There's not much TH at 6mg, so 11mg might be better for you if you want TH. You can always set the pre filled cartos you purchased aside, for those times when you're having a serious nic fit. Like when you first wake up in the morning. Then switch to a lower nic level for chain
vaping. Once you finish a pre filled carto, you can set it aside to refill with your own juice.