Of course every brisket is different but there are a few things that you might want to adjust.
Try to trim the fat cap to about ΒΌ" and do the same with the hard fat ribbon between the flat and point. Seasoning is an individual choice - I'm usually a "purist" (salt, pepper, and a little garlic) but everyone is an expert and there really is no wrong answer.
If you want, you can always rack the trimmings above the brisket to allow the melting fat to drip down and "baste" the brisket. Some people (especially those who smoke fat side down) swear by this; others say it's totally unnecessary. I do it depending on how I feel that day and how much room I have in the smoker.
You found the main problem with smoking a whole packer - it's easy to dry out the flat while cooking the point to perfection. Usually if you get the flat right, the point will be just fine. I usually don't even eat them at the same time, saving the point for burnt ends, the world's best chili meat, great sandwiches, or something else altogether.
I usually smoke at a relatively low temp for 4-5 hours and, if I'm finishing in another cooker (e.g., the house oven), make the transfer, racking the meat over a pan of liquid (drippings, broth, whatever). Continue cooking at about 250o until the IT is about 165o and then (optionally) wrap in foil or butcher paper to get through the stall.
Wrapping might be easier (and I do it about 3/4 of the time because I'm lazy) but it's essentially braising and will not give you the same nice dark bark as cooking "nekkid." In any event, once your IT (in the middle of the flat) hits about 185o, start fork-testing the "thin" end (with a two-tined carving fork) every five degrees until it's ready to break apart. Check the thick end (under the point) too, but the thin end is the key. You will usually only need to go to 190-195o but might get up to 200-205o on some packers. Temp is only a guide - the fork is king here.
When it's done, FTC for 2-4 hours, then eat. If you're going to store for a while before using, add a splash or two of liquid (drippings, broth, apple juice, etc.), rewrap in a double layer of heavy foil, let cool, and freeze.
I'm sure several of the brethren (and sistren) will have completely different advice but sorting all that out is what makes it fun (eventually).
