Final questions before first brew

About to brew my midwest Irish Red Ale and have a few questions before I start
6lbs gold LME
specialty grains
hops
safale s-04 yeast (dry)

1) I'm doing a partial boil. Palmer suggests to reduce carmelization you can add some extract at the beginning of the boil, and the rest with 5 minutes left in the boil as most extract have already been through a "hot break". Any issues with doing that with my above recipe? So say 2 lbs at the beginning of the boil, and 4lbs with 5 minutes left?
2) I'm planning to leave in primary for 3 weeks with no secondary, since this is my first and don't want to make it too complicated by adding a secondary. Any issues with this for this style of beer?
3) kit came with an LCD thermometer. Can I attach and leave this on bucket all the time? Or will i have to replace it with each batch when I wash the bucket?

1. That sounds fine.

2. That sounds like a good idea.

3. Yes, you leave it on all the time. The only time I've had a problem is when I did a water bath to cool my fermenter- soaking in the water ruined it. Washing it is fine, though, and didn't harm it at all.

Good luck! It sounds like it's going to be a good beer.

As usual, Yooper nailed it!