-Is there a negative effect of not completing the reentry permit process? Say you filed the application and then you were unable to show up for fingerprinting due to being out of the country. or you completed it and cancelled your trip and stayed in the US.
The I-131instr.pdf has some remarks to this:
However, if biometric collection is required and the applicant departs the United States before the biometrics are collected, the application may be denied.
You can have the permit be sent to an overseas US consulate. Depending on your concrete timeline and reasons, you should get an InfoPass and discuss this with your DO (see below)
-Is there a way to expedite the reentry permit process, or at least the fingerprinting so that you can file and have your fingerprint done asap and leave the country?
USCIS lists criteria under "Tips for Filing Petitions and Applications to the NBC":
under I-131:
.......
Expedite Requests
1. If an applicant has an urgent need to travel and has already filed an I-131 with the NBC, the applicant or his or her representative should visit the local Field Office by making an InfoPass appointment or call the National Customer Service Center (NCSC) at 1-800-375-5283. The Field Office will consider the merits of the request, and will forward requests that they determine to require expedited handling to designated points of contact at the NBC.
2. If an applicant has not yet filed an I-131 and needs an expedited Advance Parole document, the I-131 may be filed in person at the local Field Office after an InfoPass appointment has been made. IMPORTANT: Note that expedited processing is done at the discretion of the Field Office, based upon the evidence provided by the applicant.
3. <snip>... I-765 application processed...</snip>.
4. Please keep in mind that expedite requests for applications and petitions will be considered based upon the following criteria:
- Severe financial loss to company or individual
- Situations of extreme emergency
- Humanitarian situation
- Nonprofit status of requesting organization advocating the cultural and social interest of the United States
- Department of Defense or National Interest Situation (Note: Request must come from an official U.S. Government entity, stating that delay will be detrimental to the U.S. Government.)
- USCIS error
- Of compelling interest to USCIS