[Android Q&A, Help & Troubleshooting] TheTehk17:
Over the last few months I have gathered together some various questions I have been unable to answer for myself or by searching. I spend 99% of my time at SDX-Developers but most of the legacy developers have moved on, and so there are few left for people to post questions to. Anyways, here we go.

I will modify this post accordingly as answers come in or I have any more questions.

1) Is there anything else in /system that has to do with keymappings besides /system/usr? There is a bug on a certain 2.2 build for my phone that causes fn+period=.com instead of fn+period=comma, like it should. Replacing the kl and bin files with ones from another build that has correct keymappings does not fix this issue, so this leaves me wondering if there is anything else in /system that relates to keymappings.

2) system apks compiled with apktool will not allow a ROM that formats data to boot. I have heard something about apktool using 'full compression' and am curious as to why this is so?

3) In some decompiled system apks, there are a certain number of folders, obviously. But when recompiled, some of these folders 'disappear' from where they were when the apk was decompiled. Where did they go?

4) I have some custom wallpapers in a ROM, but the filesize for each is much larger then the stock wallpapers. I found pngout to decrease the size, but all it does is increase the filesize. Is there a combination of settings for pngout that will work best?

5) There is a bug on a certain 2.2 build for my phone; basically, Contacts.apk has horrible performance. Scrolling is laggy, Home ---> Contacts window transitions are laggy... everything that deals with Contacts.apk is laggy. Memory leak? Bad code? I did a logcat and no errors showed up, but I do not know how to look for a memory leak.

6) There are six numbers in /sys/module/lowmemorykiller/parameters/minfree. What programs do each of these individually relate to? I know that these numbers are in pages and when free memory drops below that point, the program related to that number is killed, I just have no idea as to what program each number specifically relates to.

7) I want to make a few preloaded appliations in my ROM uninstallable by the user, so they would not have to go through the trouble of manually removing it themselves, which can be a bit over-the-head for new root users. Anyway, I did this by creating /data/app in the root directory of my ROM and adding copy_dir PACKAGE:data DATA: to the update-script. The apps I put there (in /data/app) were in fact uninstallable in my testing, but reappeared after a reboot... so I am stuck. I am thinking I may have to set permissions as well in the update-script but am not quite sure.

8) What does everything in /proc/sys/vm do (individually)? What would the end user notice if these files were edited?

9) What is VR I/O schedualing, CIFS, LZ compression, BFS? And how would I go about removing certain available CPU frequencies (some kernels for my phone have 133MHz removed for faster wakeup), undervolting, and increase the USB draw? I have successfully compiled and booted my first kernel, but am unsure of how to apply different modification outside of what is available in the menuconfig.

10) Zipaligning apks is supposed to reduce their RAM usage. In testing, I zipaligned Browser.apk and it used no less RAM than when unzipaligned. What gives?

11) 0-compressing icons or apks? How to do this? I know that Photoshop lets you chooose the compression level but that reduces quality, so this must be different.