First off, without knowing what the PG:VG ratio is for the juices you buy and like, its impossible to say what mix you should make in DIY.
I would post this in the DIY forum, if you have not already. Your amounts seem fine for the nic level you want. PG vs VG vs mix is by your preference. Some, like me, can not do much PG at all, if any. Some prefer all PG, no VG. Some like a mix of the two. PG effects are more drying of the mouth and throat, badly in the extreme, just increased TH and flavor perception for other. PG dries me out horribly. I make only VG juices. VG moistens, and adds vapor production. Some say it reduces flavor, but my 10% flavor juices, and several with less than that, taste just fine to me.
I would make 3 mL samples of the juice you want, one with all VG (add about 12% water, the flavor will also thin it some), one with all PG (no thinning needed) and one with maybe 50:50 PG:VG. The vape one of them for a while and see how you do over the course of a day. That will give you a good idea of your tolerance for PG. If you find that you have to continually drink water and yet it doesn't help the dry mouth, go with more or all VG, as over time this will lead to more problems. I actually get gastric issues from PG too, not just throat and mouth.
DIY, even when using a spreadsheet to calculate, is an ongoing experiment. Some flavors do great at 10%. Some should not be over 1%, like some PA coffees. You have to try things with small amounts first. And some flavors you buy are not quite what you were looking for. DIY juice making is like cooking. It takes practice to get what you are after. All the spreadsheet tells you are relative amounts, which helps in making a juice that is the right thickness or thinness for your application (dripping likes thick, cartos like thin), but it doesn't tell you if it is good, or if you will dry out too much. Only testing a juice out will tell you that.