First, it sounds like you might have accidentally put a battery backwards inside your Neon (happens all the time). That'd account for the leakage/gurgling sound.
Secondly, transmitters EAT batteries. A full charge on a Futabe 6EXA lasts around 3-4 hours max. You really want to stick a Nicad set into there - get some of the 1250 nicads for sale at Wal-Mart and you'll be very happy!
Now, for your motor. You'll want to get a more powerful motor than a standard "can" 400. They're inexpensive, yes, but they wear out quickly and without the right voltage can simply "poof" into non-existence.
I have a small fleet of EasyStars. The one I use most (I use it for aerial photography) is fitted with an Astroflight Brushless MightyMite 010 DD motor. I run a 3 cell, 1500 mah Lipo battery for a total of around 60 minutes flight time. This motor will make your EasyStar head skywards FAST, and it only draws 7.5 amps compared to the +/- 15 the 400 does.
Take a look at Tower Hobbies. This motor is used for the Trick "Zagi" series of planes. It's set up for reverse rotation (which you want), and should drop right into your EasyStar with no modification at all. It'll provide a very good performance increase.
I know you're looking to keeping costs down, but for future purchases consider investing in a good LiPo battery. They're almost literally worth their weight in gold.
Flyer