Are you really looking for a pod system? Or did you put your inquiry into the wrong sub-forum. I don't believe you'll find a DTL pod system, but I could be mistaken. All of the pod systems are MTL.
If indeed you are looking for a pod system that allows you to add your own e-liquid, reading this thread may help narrow the choices:
Which pod systems allow you to add your own e-liquid?
I'd suggest just about anything else over a SMOK product if you're looking for something that should last over a year. Having worked in the retail end of the industry in the recent past, you'll never see me recommend any SMOK product.
Smok
About your criteria of choice...the below answers relate more to a non-pod system.
1. No nic salts is easy enough to accomplish if you use any "open" system that allows you to add your own e-liquid of choice.
2. Relates to #1 above. You can put your e-liquid of choice into any open system.
3. You should be able to get 7 - 8 hours battery life with any 1200 mAh or higher battery. Depending upon the coil resistance you will use, wattage power of the battery device may be be more of a priority than mAh. In general, the higher wattage battery devices have more than plenty mAh battery life.
4. Basically, any clearomizer tank will accept premade coils.
5. Throat hit is the product of the nicotine concentration of the e-liquid. Pg has a minor contribution to the throat hit. You may need to increase the nic concentration of your e-liquid from just 1.5 mg to something higher. I wouldn't depend upon a high Pg ratio to make up the difference in throat hit.
6. There are more DTL clearomizer tanks on the market than MTL. Nearly all of the sub-ohm clearomizers are DTL. To perform adequately, using a sub-ohm tank requires a minimum of wattage power from the battery device. Generally speaking, a 75 watt regulated mod will be able to fire most sub-ohm coils. Coils will have a recommended wattage range displayed on the coil itself, or on the product description page. Just make sure that your battery device can supply the recommended power (watts) for the coils you use.
This blog may help you narrow down your search:
Good Starter Setups for a Beginner Vaper