Hi, Sherry! Don't worry about the questions - that's what forums are for!

First, I'll address your question about cost. It can get very pricey changing platforms from PPC to Palm OS if you have very many applications. Depending upon the software developer, they may be willing to give you registration codes for your new platform (I did that with my Astraware games), but not every developer will do that. It also depends on whether or not your programs are available in versions for both platforms (many of mine were not).
As to why LDW releases games first on the Palm - it's because they find that it works best developing for Palm (the trickier platform), and then porting to the PPC.
The displays on my T5 and my Zodiac 2 are not as nice as the VGA display on my hx4700. And my Zodiac 2, even on full brightness, is dimmer and 'yellower' than my T5. It still looks good, and you don't notice unless you have the devices side by side. The Zodiac displays Village Sim and other traditional Palm games in the usual square format. Unlike the Pocket PC, many Palm games do not support full screen mode. It's easier (and cheaper) to offer one version of the game that supports the vast majority of Palm devices in use (PPC applications are all full-screen). The Zodiac operates normally in landscape mode, because the layout of the controls is similar to the typical game console controller (GameCube, Playstation, X Box etc.) If you intend to play 'action' type games, that can be very handy. Most of the games I play don't use those controls, but the solitaire program that comes with the Zodiac lets you use them to play without the stylus. That's handy. Since Village Sim and other 'square format' games don't take up the whole screen, you have your choice on the Zodiac to display it in the center of the screen with margins on each side, or on the side of the screen with the normal graffiti silkscreen displayed next to the game.
Graphics accelerators are not programs, rather they are part of the hardware built into the device. Depending on the type of accelerator, it can provide a big performance boost with many games. It all depends on the game and the hardware you're using.