I think your system is good enough that you are going to have to spend a bit more than $500 to get a big improvement.  I would upgrade speakers if it were me.  Athena, which is a brand of the parent of Energy Speakers, has last year's models on sale at 
www.audioadvisor.com for good prices.  You could pick up a pair of B2s for $150 or B1s for $100, and a C1 for $100, to replace the front 3 speakers from the Take5 package.  That will give you a little more midrange performance.  You then have the extra speakers to use elsewhere - perhaps down the road you could upgrade to a 6.1 or 7.1 receiver and use those speakers to fill in your surrounds.
You can get a decent universal remote for about $100.  The URC-200 is $92 
here.  It's easy to program and easy to use.  The 100, with a smaller display is just $62 from them!