Marlin Firmware Upgrade problem

I have been working hard core for the past 2 days trying to get mesh bed leveling to work. In all honesty, 2 days ago I had never heard of mesh leveling before, nor PID tuning or anything. I didn't know who the heck Marlin was but everyone was talking about him, so yeah, I had no idea my Robo ran off Marlin. The point I'm trying to make is I was starting with almost 0 knowledge, and I have read countless posts trying to work out all the problems on my own to minimize the number of questions I ask, but I've hit a dead end and need a little extra help so I appreciate the help.
Here's where I'm at...

1. I replaced RCBugFix MESH Bed Leveling firmware with RC8 MESH Bed Leveling firmware, updated the PID settings and selected the correct LCD, but now my LCD screen displays a funny thing for my nozzle temp. It would show dy.9/0 and the number 9 would fluctuate between 0 and 9 (see attached picture). Even when I heated my nozzle, the 0-9 fluctuation wouldn't change. When I went back to the 4/16 firmware it displayed fine and worked as expected, then I would go to the previous stable RC8 mesh bed firmware, and again, it would display "dy.9/0". Now it appears to be stuck at 9.

2. I haven't been able to get mesh bed leveling to actually work, and I really don't know why. When printing large items, the first layer is very inconsistent. I went through all the necessary leveling steps on the LCD screen and did all 25 points, with the piece of paper under the nozzle and everything (I did this with a hot bed and nozzle, and obviously with no oozing, but I also tried cold). I saved the mesh to EEPROM, and I checked the mesh points using G29 and they're all there. This is exactly the same problem I originally had with ABL (both the stock, and the one in the latest Marlin 1.1.0), and in both cases I can see the Z axis moving ever so slightly as it's printing, which means something is working, but I can't figure out why the first layer is always really squished on some parts of the bed, and not squished nearly enough on other parts. Any ideas?

 

I followed the mesh bed leveling routine through the LCD and did all 25 points.

@WheresWaldo, that's just it, I tried modifying so many individual points using "G29 S3 Xn Yn Zn.nn", then I verify that the changes have been made with G29, then I save with M500, disconnect from Pronterface, launch Cura for Robo, try to print, and it prints with the same unevenness. Come to think of it, I've only noticed the Z axis moving during a layer print once.
And for some reason on my latest few print attempts, I noticed that my Z axis was no longer moving up and down to compensate, which I found strange, because it was doing it earlier... Do I have to do something to activate the mesh before printing or something? I have this in the beginning of my gcode:

Code:

G21        ;metric values
G90        ;absolute positioning
M82        ;set extruder to absolute mode
M107       ;start with the fan off
G28 X0 Y0  ;move X/Y to min endstops
G28 Z0     ;move Z to min endstops
G1 Z5.0 F9000 ;move the platform down 15mm
G92 E0            ;zero the extruded length
M117 Printing...  ;Put printing message on LCD screen

 

Thanks for the suggestions. I'll implement those in my beginning gcode. To answer your question about what firmware I'm using, at the moment it's the 4/16 BugFix Mesh Plus one, but as mentioned in my first post, I tried installing the RC8 one, but as you'll see in the picture I posted in my first post, it does this weird thing with the nozzle temp on the LCD. Is this normal or no?

 

Well I'll be damned... I installed RC8 instead, and ignored the little glitch on the screen. After starting my first print, it corrected itself and the LCD screen is displaying everything fine now. Not only that, I went through the 16 point mesh routine on the LCD (so much easier than doing it on the other RCBugFix firmware!), saved the mesh, tested a print, and the initial skirt, which spanned almost the entire bed, came out perfectly! The Z axis was moving and everything. So apparently RC8 fixed all my issues!
I feel like crying.

Anyways, thanks so much for the help.