Is it ok to crimp Romex to create a longer run
There are lots of devices besides wire nuts you can use to splice Romex in a junction box, but generally splices outside of a box are prohibited.  The Spliceline push in connectors, insulated crimp connectors, any of them - has to be in a box.  

There is a device made for Romex repair that is used to splice Romex outside of a box, but it's in a gray area, it's listing is for use in manufactured homes.  So it's OK for use in mobile homes, modular homes, etc., but not for built in place homes.  Some disagree with that, and use these devices in any kind of building.