I do not know if it's possible to add these options to Qlik's default new app creating process without "hacking" into QS code, but I do think that you can use few options to simplify your Development process:
1. You can create a set of script files to be included into each application (DB connector strings, variables, etc). So the only thing your developers need to do is to add one of few "#include" statements into the script.
2. You can create a template App (with all necessary modifications) and publish it into "Everyone" stream. So your developers will just need to "Duplicate" this Template app into their own Work stream and start adding their code.
P.S. When applicable, please mark this answer Correct or Helpful.