Slicing with cura, hitting bed

Just looking at the giftbox code, I notice that your speed is set very fast (not related to the problem your having, but will probably cause you issue's).

Your version of Cura is setting the first layer start at .35 above what Cura thinks is Zero. I have mine set to .3 first layer so I'm running a bit closer than you are, but the problem your having is that your Zero in firmware isn't very close to reality.

The best solution if you plan on using Cura is to slice a file and then edit it. Have the head move to whatever distance you've set the first layer to (appears to be .35) but edit it so it NEVER attempts to go over the glass. Once it does this move and then stops, turn the printer off and adjust the screws until you have a .35 gap when you move the head over the glass.

I could be wrong since I'm not and expert in gcode, but I'd think changing the line in your labyrinthGiftBox_bottom.gcode file at the top of layer 0 from G1 F4200 X92.660 Y74.957 Z0.350 to G1 F2700 X0 Y0 Z0.350 would make the bed go to the right level but have the head stay parked, you delete the rest of the file after that. You would then be able to turn off the machine and start adjusting until you have a real 0 on the Z setting.

The problem is the order it's being moved in. First the platform is being moved down 15mm, then it's coming back up to .35mm of the head and it's hitting because the Zero isn't as Cura expects it to be.

The solution to making all of them work is to "Zero" as Cura expects it to be then rerun the DaVinci firmware bed level until the two match the same spot, or do a manual edit of the Z Zero position with a G92 command. The "code" fix version is detailed below.

Courtesy of RepRapWiki
"G92: Set Position
Example: G92 X10 E90
Allows programming of absolute zero point, by reseting the current position to the values specified. This would set the machine's X coordinate to 10, and the extrude coordinate to 90. No physical motion will occur.
A G92 without coordinates will reset all axes to zero."

So to do this just for Cura, you'd need to slice with XYZware, turn it off before the print knowing that the first layer is about .3 for the head above the plate. Measure the distance. Slice with Cura, turn the printer off when it does the 15MM move and measure that distance. Do the math, add the G1 Z?? then a G92 Z0 added to the code at the start of the gcode Cura generates or have it do it as part of it's start section. This would involve a bit of work, but would solve the issue. If you can't measure it easily, just start with a safe value (say 5mm) keep backing it off .3 at a time until the filament is close enough to stick to the glass. Then .05 or less until your satisfied with how much a line "flattens" on the first layer of a print.

Rudster, I'll guess the hotend stopped heating? If so, it's a known issue and you'll see multiple posts about it. The connectors for the cartridge heater are garbage. I solved mine by solder, others swapped out the poor connectors for deans plugs.

As to the curling, that is something that can be mitigated if not cured. I won't promise your printer will perform the same as mine, but the hotbed on mine can go up to 115C. Which honestly is beyond the point where any of my "surface prep" other than abs slurry stay effective. I prefer hairspray and that tends to not like that much heat. But on a level bed with the first layer being printed close enough to "flatten" a little on the glass, I just don't have the print lift off, even if the corners warp a little.

Putting down a 20 line brim and getting good adhesion on that first layer is enough to make most of my prints usable if by no means perfect.