Is this a 3-piece? The stuffing needs to be wet until moist on top but not a puddle. The stuffing need to be positioned near the top of its juice cup and fluffy enough to stay in place ok. I've used a 3-piece a lot - they require more fiddling with than a 2-piece.
I don't know what model Puresmoke is. Looks similar to RN4081 atty but with female threads on atty instead of male. No idea. Their prices are a bit high. Prefilled carts (the kind used with atty) should cost more like $10-16 for 10, batteries should cost $12-15, maybe $19 for a fancy color, attys should cost about $8.
Re burning throat
1. do not inhale directly as you drag. drag then inhale
2. drag slowly
3. If a manual, press a bit before you start dragging and let up a bit before you stop dragging, then inhale
If auto (which I do not use) you may need a warm-up short drag if the atty is cool, then your real drag.
Also, if the battery has a short safety cutoff, long drags may trigger a cutoff which will keep the atty from turning on for some period of time (10-90 seconds)
4. if it was super-harsh when you first started using the atty, that can be primer on the atty
5. if it's ok some times and harsh other times then it could be singeing the stuffinf. check is it needs to be topped off with juice
What juice are you using? If it's 100% PG or especially high nicotine and 100% PG then yes, it is harsh. I usually prefer 70pg/30vg juices.
And as mentioned, vaping can be drying (especially 100% PG which makes my tongue sore and some peoples throats sore). Sip at fluids.
BTW - if you have 100% PG base juice, you can tone it down with VG though it will cut the nicotine level and flavor too. But even 10% VG may help. You can get USP Glycerin on the shelf in Walmart near the rubbing alcohol. You may also be able to get the pharmacy to sell you an empty eye-drops type bottle and they should sell separate droppers too. Shake your juice (always shake before using too), take 9 parts of your juice and mix with 1 part Glycerin in the new bottle. if that is still harsh, try adding more glycerin and shake.