Removing 1 year old stain

I live in Dallas, TX and we added a deck on to a covered porch. The porch is redwood but our deck that we added is treated pine. It gets mostly full sun. I used a semi-transparent stain last year on just the new part and I hated it immediately. The color was wrong, it went on horrible, etc. I’ve lived with it for a year hoping some would fade off since we only did 1 coat. Since I knew I didn’t like it, we didn’t even put the stain on the sides....only the top. I hired a contractor to come power wash it and restrain it. He just finished the power washing and there are still a few spots that have stain in them....like knots or deep crevices. Also, some of the Wood appears fuzzy now. The stain was a light grey color but I’m wanting to go dark, like pecan or walnut. My questions are:
1) does it matter if it didn’t all come off....if so what do you suggest doing?
2) do I need to sand the fuzzy parts?
3) can I stain the redwood the same color as I do the pine and will it look similar?