The sample files have a brim if I remember correctly, which helps the print stay fixed to the bed. I had moderate success using ABS slurry, but ended up importing slic3r code with a brim into XYZ software to compensate. Ultimately I flashed repetier so I could change temps to 230/230 and 90/90 for extruder/bed first layer and subsequent layers respectively. Id recommend starting to play with slic3r and openXYZ mod to get your feet wet with brims and temps. If youd prefer to stay stock, raise the bed slightly by adjusting all three bed level screws a quarter turn so the first layer has a fighting chance of sticking to the bed. Do this AFTER you're calibrated and the offset is stored in firmware, otherwise the new offset will take you right back to where you were originally.
Only going to ask this because you said novice user.
You are using some adhesive to have the ABS stick to the glass correct? I like Elmer's Glue sticks, others like Blue painters tape, etc.
Well, I know that glue is absolutely necessary so I used it, but it was not very good (some places sticked, some did not = warping). So after some browsing online and trial and error ABS juice moro or less works OK. It is kinda tricky to get the concentration right but compared to glue I'am getting much better results. Now when I would just get the Xyzware openmod working properly for me everything would be perfect.
I've only had my da Vinci 1.0 for about a week so I'm a novice as well, but I have a few observations that might help. As you know when you get the printer out of the box, there are instructions that tell you not to do a calibration as it has been done in the factory. The instructions also tell you that the calibration numbers should be between 200 - 250 and within +/- 20.
The demo prints came out fine, but I think (as others have stated) that the g-code has been tweaked. I have a calibration print that is the bottom and 2 adjoining sides of a small cube 25mm x 25mm x 25mm with 5mm thick walls. When I printed this, the bottom layer (or 2) were squished so there was a noticeable lip along the bottom. When I did the print with a raft (hopeless raft of 1 layer) it was stuck so well due to the squishing I couldn't remove by hand or pliers. It had to be cut or sanded off.
I checked the calibration from the factory the first number was 265 and it actually failed (other 2 numbers more than +/- 20). I recalibrated to around 225 and the lip disappeared from my prints. But I did get some prints lifting if I didn't have enough glue on the glass, I had to put it on a little thicker. I now leave the old glue on and just run the glue stick over it lightly. After the glue layer looks to thick (3-4 prints) I clean it all off. I have since re-calibrated back to 265 to try and fix another minor problem I've found. I might try around 240 next.
So yes, the bed height will have an affect on the print sticking but it can be overcome with a bit more glue. I'd suggest that on a clean glass plate you apply a couple light coats of glue stick on a hot bed waiting for each coat to dry.
Hope this helps.