Freddy,
Seems like you're on the right path. I got into straights for the exact same reason you did. Curly beard, ingrown hairs, irritation.

I have to really pay attention to my angle when the razor width changes 2/8, 3/8, 7/8 etc. It doesn't make a lot of sense to me, but it certainly makes a difference.

Also, I used an 8k to shave off of for the first few years and got to where I was quite happy with it. Then I ran across a Thuringian and by comparison the 8k felt like shaving with a serrated blade. If you've eliminated your ingrown hairs and irritation shaving off the 8k, you probably don't "need" a finisher, but you'll probably really enjoy having one once you do. When my razors need a touch up I run them on the Thuri and shave directly off of that without stropping and it's like a sweet dream.

Peace,
Jim