Since people don't seem to be answering your question in its entirety, I will give it a shot.
- DWR is just a coating on top of a fabric. It is helpful in water-repellance, but you are in wet conditions continually then you still need a jacket whose fabric has smaller pores (that is what the number of waterproofing represents).
- Is it worth going Gore-Tex? Gore-Tex is actually a company that makes a specific type of fabric. They have obviously done well for themselves and make a great product. Just because a material is Gore-Tex doesn't necessarily make it super rugged. Gore-Tex has become very popular because it has a high waterproofing and breathability to weight ratio. eVent is also becoming increasingly popular for that reason. So, you can get Gore-Tex, but other types of fabrics still provide high waterproofing and durability as well
- 2L and 3L refer to the thickness of the jacket, meaning that it is made of 2 layers or 3 layers of the material. The more layers, the more waterproof. For example, two layer Gore-Tex is 28,000 mm and three layer is 45,000 mm. Another example would be North Face's most popular middle to high end fabric - Hyvent. Many jacket sport descriptions that say Hyvent 2L, which means it is 2-layers of the fabric welded together and reported is around 22-25k waterproofing. So, it has nothing to do with a poly-coating or spray.
- No idea about moment stuff, but if you are really looking forward to getting a nice, durable and waterproof jacket, buying the first year of any line isn't necessarily recommended.
I hope that helps you and find a great jacket. If you want my personal advice, then go for a company that isn't adult-world mainstream but uses a high quality fabric. For example, when you buy Arcteryx, North Face, Norrona, Mountain Hardwear, etc, you are paying for their name as well. I have found that you can get good used gear by keeping your eye out and buying a more core brand that employs a good fabric. For example, I had a DC Venta jacket that used 3L eVent fabric and it was $50 new. I sold it, but it would have lasted for many seasons and was 30,000 mm waterproofing. Hope that helps. PM me if you would like any specific suggestions