How to increase internal memory of the HTC Wildfire S finally?

I've been spending a lot of sleepless nights trying to fix this. I know there are a lot of threads like this on the internet, but I want to go a bit deeper. I have an HTC Wildfire S with only 512 MB internal flash memory. This internal memory has a partition layout allocation around 130 MB for the /data partition and around 290 MB for the /system partition. Both of them are full. (In addition I got a 16 GB SD-card.) Installing apps, upgrading apps, running most of the apps - impossible. Now, I knew it's possible to move apps to SD-card, the so called **apps2sd** procedure which offers very limited functionality to move *some* of the application data to the SD-card. Anyways after moving every possible data to SD the internal memory was still full and the phone unusable. I was reading about more sustainable methods like **data2sd**. I gave it a try. I used the instructions from htcdev.com to unlock the bootloader , I installed the latest ClockWorkMod Recovery and rooted the device permanently. Finally, I used the rooted device to install Android 4.1.2 AOKP Jelly Bean Custom ROM and Data2SD like discribed in the linked articles. But I was stuck the device was not booting until I removed Data2SD. The AOKP-ROM was working pretty well and stable, but installing Data2SD simply did not work in combination with Jelly Bean (SD-card formatting: 11 GB FAT23, 4GB ext4 and 256 MB Swap). Now, I tried to go for the **link2sd** approach. I reformatted my SD-card (14 GB FAT32 and 2GB ext4) and installed Link2SD on my phone as described here . I was able to move additional data and apps to my SD-card and could link some apps to the card. And now after some days playing around with all that usefull tipps from the internet, for example this thread: https://android.stackexchange.com/q/2065/29916 - **I am at the point where I started**. This is my result: Internal memory is still full and the phone is still unusable. (I would love to post a screenshot, but taking screenshots simply does not work currently.) How to finally fix my internal memory on the Wildfire S? Why is Data2SD not working with the Jelly Bean ROM and why is Link2SD so ineffective? Is there anything I'm doing wrong? The main problem seems to be the Dalvik Cache on the /data partition (around 100 MB). Is there any way to completly use the SD card to somehow get partitions mounted at /data and /system?