I think most of your questions have been answered but I would like to throw in a few comments.
1) The format of the form is irrelevant. The content of Table 4.12 must be addressed and recorded. (Process, F-Number, Position, Diameter, Thickness, Vertical Progression and Backing. The digital form in fillable PDF is at https://app.aws.org/technical/forms/N-4.pdf
2) As indicated, you must use the joints as shown in clause form. A prequalified joint design exists in clause 3 that will match the details of the required joint designs in clause 4.
3) There are prequalified partial and complete joint penetration joints however there are no PJP joints for welder qualification.
4) The employer should have their own WPS's and of course you can prepare them for them however they need to have signature authorization somewhere on the form. I try to stress to organizations who are wanting their welders "certified" that there is more to code compliance than just that and having a certified welder will typically not release them from the responsibility of their work and though they may be able to show intent of compliance by certification of the welders, there is usually a great deal many more requirements within the code .
5) Submittal to AWS is only a requirement for an AWS Accredited test facility.
6) If you have the equipment to pull tensiles, you can pull them but don't forget the need for NDE prior to bends/tensiles.
If you are near NE Tennessee, I am planning a series of inspector training sessions this summer and welder testing and certification will be one of the modules (6-8 hours tentatively).
I apologize for duplicating any other responses. Just remember that welder testing is only a small part of code compliance and producing quality welds.
Have a good day