I have never used number forwarding. I have a choice of carrying around a second flip phone or forwarding the number from verizon flip phone to my mint mobile semi smartphone.
If I use number forwarding can I identify which calls are forwarded? I ignore all unknown numbers coming in on my personal cell.
Please tell me there is a way to have messages forwarded to my smartphone instead of the dreaded flip phone texting.
You can forward calls and still be able to see who they're from, but there's no way to forward text messages, that I know of.
Google Voice
Ummm... no.
Google Voice will not forward text messages sent to a phone's native number.
I don't think we're all quite on the same page here.
Google Voice can forward incoming texts sent to the GV number to a linked phone's native texting app, if desired.
Google Voice can't forward texts or calls placed to a phones native number (carrier-supplied number)-- which is what Chelle is pointing out.
I believe Chelle is correct that while traditional call-forwarding (without GV, but using your carrier's call-forwarding feature if available) might be a solution for incoming calls, it's not a solution for forwarding texts.
I'm assuming als (the OP) isn't using Google Voice as his outward-facing contact number. If he is, some possibilities would open up.
You (and Chelle) are 100% correct (as usual) on all counts with 1 addition: You can port your mobile phone number into Google Voice thereby enabling all the possibilities we are talking about. Sorry I gave a "drive-by answer" before without elaborating as I was somewhat busy at that moment but wanted to give some quick advice. 
Google Voice would be my starting point for als' problem, too, johnsmith! I think it could supply the functionality needed.
Having gone through that situation once, I know it's not always easy to port a needed # to GV.
Timing can be pretty critical for making the jump to GV, since plans can be sometimes be lost or forfeit in the process. I've been happy that I made that jump, though.
I don't know if als' flip-phone and semi-smart phone are android-- a dumbphone complicates the issue a little. (I looked, and the newer KaiOS flip phones don't seem to have access to the GV app.)
But the problem of texting on the flip phone could be avoided, since the flip could receive a text, and the semi-smart phone could reply while presenting the same number to the person on the other end. (Only a phone capable of running the GV app would have a record of both ends of the text conversation, though.)
And calling out from the flip phone (assuming it's not Android) could be painful to get it to present identity as the GV number.