Could try this firmware
http://www.firmwarehq.com/NEC/ND-3450A/files.html
Your issue is a crappy burn that can't be read. Also try to slow down the burn speed to 4x.
A cleaning disc might help.
Verbatims could be worth a try.
If the above fails, get a new burner.
You probably have your hard disk formatted as FAT32 and by doing that - it can't create a file bigger than 4 GB. So it's splitted into pieces. Convert the hard disk to the NTFS file system if you want a single file.
Use the .mds file when you burn the project.
Sounds as you have the files in another format than this:
I guess that's why your DVD player refuses to play the disc.
You can use this program to convert the files to DVD compliant files.
http://www.dvdflick.net/
Yes, that would give you the answer of two things;
1. Can it burn a disc without erroring out
2. If it book types
Just remember to have the "Verify" option enabled in ImgBurn.
You should see the book type in the verify part of the log when you have burned the disc.
It's a rebaged Lite-On 1633S so my feeling is that it will book type +R DL media by default. If that is not the fact, it's possible to flash it to be a Lite-On with booktyping.
Not all burners accept commands to change the book type and that's why they are not listed in the book type section of ImgBurn.
The other thing that also might be an issue is what type of media brand/media code you are going to use with this burner. It's pretty old (2004) and you are likely to run into problems with newer media codes.