Install data directly to SD card

[starfighter9]

I have a HTC Wildfire S (Android 2.3.5), and the internal memory is really small at 150MB, with a third eaten up by the default apps and whatever. I also have a 16GB SD card, but it might as well be a potato chip since I can't get the phone to use it. There is a function to 'move to SD card' but it's pointless since the app I'm dealing with has an initial install of ~50MB but later on downloads up to ~300MB, so it hits the limit and stops there, also it refuses to let me transfer any more than the initial 50MB. Is there a way to force all apps to install everything, including downloaded data to the SD card by default instead of the phone memory? I searched the internet and various sources say rooting can allow you to transfer data but I couldn't find anything on directly installing to the SD card. My phone isn't rooted, but if required I have no problems with doing it (I've never rooted it before though, so any tips on this would be welcome too).