IMO dust isn't really that much worth worrying about. Just wipe it off with a clean cloth or, in a pinch, your shirt tail. Nothing wrong with the blowers or the brushes, I just don't see the point in carrying another big piece of gear. I have a small blower/brush that I got in a kit somewhere, and I use it when I'm in the mood, but it doesn't travel with me.
About UV filters. Your kit lens is worth about $100. A decent UV filter will cost at least $30, and it will still get in the way and cause possible image quality problems. If your lens gets really beat up then you can probably have it repaired for the cost of 1-2 UV filters.
I have about $4000 worth of Canon lenses (including a couple in the $1000 range) and do not use UV filters on any of them. The high-end filters necessary to avoid image degradation would run over $100 apiece, and guess what it costs to send my lens in to Canon and have them replace the front lens element if it somehow gets damaged badly enough that I can't stand it? Not much more than $100.
The UV filter vs. not debate has raged for many years. Both sides have their partisans. I have seen that small amounts of dust and even small scratches on the front element really don't impact the image in any visible way. The added bulk, expense, and hassle of UV filters for not any noticeable improvement has made me say no to them. There are people who like them, though, and count them as an insurance policy for their lenses. I put the hoods on my lenses and that is pretty good protection for when I'm using them. I won't call you an idiot for buying UV filters, but personally I have weighed the options and decided against using them.
It is the same thing with the screen protectors. You spend $20 on one, put it on and it makes your LCD look like crap while also leaving crummy residue and blah blah blah. You can get the back plastic covering over your LCD replaced with a brand new one for like $30. It takes 5 minutes to do it. No reason to protect something that's so easily replaceable. Again, JMO like with the UV filters.
An upgraded neckstrap and carrying bag is a good idea. I like the Think Tank Digital Holster line. I think the Digital Holster 10 would be plenty big for your Rebel. You can carry it over your shoulder with the included strap, or put it on your belt. Pretty handy and it's small and contoured so you can throw it into another bag/backpack/luggage/etc. if you want. But it's also super sturdy and well padded.
A tripod is another good idea. There is a whole lot of stuff to get into there. In general you are looking at spending around $200+ for a good quality tripod and head. But for starting out you can just find a cheapy somewhere. Look on craigslist and you might find a good deal on a higher quality tripod. I have a favorite mini-tripod, the Slik Mini Pro V which is available at Amazon for $30. It is small, but quite high quality for the price. It is small enough to be easily packed and carried -- I just hook the handle over my belt sometimes, or it will fit into a large pants pocket. It is very sturdy and can safely and securely hold all of the gear that I can throw at it. (Big camera + big lens + big flash) It is great for getting low shots; and for high shots, you can set it on top of a table or car or rock or whatever you have handy. I wrote a review of it here:
http://photography-on-the.net/forum/showthread.php?t=721288
I have used both the Slik Mini Pro and the Think Tank Digital Holster 20 to take photos when hiking/camping in the back country. They are both perfectly suited to it IMO. You can easily find a bit of extra space at the top of your pack, or if you're in "active shooting while hiking mode" then you can attach the holster to your backpack waist belt and slide the tripod into an extra strap or water bottle holder.