Some unresolved but important X.org problems

I have been having problems described below since March of 2014, but did not have much of an option other than to wait for gradual improvements. Considering that 11 is nearing official RELEASE, I would think these problems would be worth consideration. I'm posting in current rather than xorg, because if there were many others with these problems, it would have been brought up a long time ago.

PROBLEMS:
1. PDF viewers fail to display pdf/ps files correctly. Many files get displayed as blank pages, and I can only get the pdf to display after closing/re-opening the file several times, or by repeatedly scrolling up/down past the seemingly blank page. Pages with an image have more problems than pages with text-only.

2. With the exception of Opera (which is out-dated), all remaining Browsers fail to display most web pages in a sane manner (Firefox, Seamonkey, Epiphany, Midori). Chrome is the worst because even with just a blank page it flickers, goes completely white, comes back as a partial image and sometimes locks X for 1/2 second or so.
Problems with the other browsers usually have something to do with sites using php (rather than static content) and I have many problems with images being correctly displayed. Among the symptoms:
* Page phases out. Mouse-over or scroll up/down resets the display (midori-on-linuxquestions.png: https://drive.google.com/file/d/0Bxs_eepbMt6qNTdaQm1pTFZTMWM/view?usp=sharing)
* PHP sites either loose track of last scroll point and jump appx one page up (example Facebook goes up 4-5 posts to what I just read and repeats action as I try to scroll down), OR they are only partially displayed and need to be either refreshed (F5) or up/down scrolling to get some kind of display (epiphany-on-forums.freebsd.png: https://drive.google.com/file/d/0Bxs_eepbMt6qbFJWMW1RZzJsYVU/view?usp=sharing)
* I get the same problem when trying to view an image, or a site with many images. The tab with the image displays one of: a black screen, a single color with vertical interference lines, or a mixture (seamonkey-google-image-search.png: https://drive.google.com/file/d/0Bxs_eepbMt6qUUJvem11U3c3MVk/view?usp=sharing)
* As a result of all the above, logging in to sites, doing any transactions which require clicking buttons and check-boxes or filling text fields becomes extremely difficult.

3. In Gnome3, menu text is garbled (gnome3-text.png: https://drive.google.com/file/d/0Bxs_eepbMt6qWklaSUZLd0luUFk/view?usp=sharing)

4. Chromium causes other programs to mis-behave and display gets corrupted in the old Win-XP style (chrome-corruption.png: https://drive.google.com/file/d/0Bxs_eepbMt6qMktnOWo3bV93SGM/view?usp=sharing)

5. An update about a month ago is causing problems with /dev/ums0 on Desktop (not vt). When I move the mouse it sometimes gets stuck on a menu item of a program or an item on the Browser (for example a result in google search). I have to move the mouse and repeat the previous action in order to get it unstuck. Sticky lasts about 1/5 of a second.

6. Last week I was getting jpeg file corruption when doing simple processing (crop, rotate) in graphics/gthumb. Resulting file would have vertical interference lines. After updating the ports/packages yesterday I don't get that now. Probably unrelated, but worth mentioning.

MY_SYSTEM:
+ Desktop is usually Fluxbox. Free Memory was 5 GB when screen shots were taken (not a low-mem issue).
+ GPU is RS880 [Radeon HD 4250], with loaded modules: drm2.ko, agp.ko, radeonkms.ko, radeonkmsfw_RS780_pfp.ko, radeonkmsfw_RS780_me.ko, radeonkmsfw_R600_rlc.ko
+ These already in /etc/sysctl.conf:
#_Enhance shared memory X11 interface
kern.ipc.shmmax=67108864
kern.ipc.shmall=32768
#_Enhance desktop responsiveness under high CPU use (200/224)
kern.sched.preempt_thresh=224
#_chromium_browser_issue
kern.ipc.shm_allow_removed=1

-- 
FreeBSD_amd64_11-Current_RadeonKMS