Dear oh dear. "F" for "Fail" for your Unify engineer. GKREG was the way it used to be configured, when you didn't do much in the card GUI other than set codecs etc. But there's a limit to what can be configured in CGWB, so more configuration has been piled into the card GUI and GKREG configuration is now no longer used for native SIP connections. You cannot use profiles at the same time as GKREG and the Unify IP solutions document itself advises profiles should be used for "more security" (IP address checking for native SIP). The old GKREG functionality is still there, but it's superseded and unless you need to address multiple endpoints there's no reason to use it, and you will lose the functionality available in the profiles if you do.
Your query above
1 - regip are left at 0.0.0.0
2 - you don't need ldat parameters for GW, they represent the GKREG entries that you should not have.
3 - in WBM, under explorers, voice gateway, sip trunk profile parameter, make sure it's set to use profiles for native sip. It is by default.
4 - in WBM, under explorers, voice gateway, sip trunk profiles, find the CUCM profile and enter the IP of the Cisco SIP endpoint under "proxy". Above that you'll probably see it's set to UDP. Make sure Cisco is the same or change to TCP (can't do that with GKREG!). Apply that config, then right click on the CUCM profile and "Activate".
That's it. No GKREG required. But remember with profiles you cannot now share this trunk with any other partner system, it will only address that IP configured in 'proxy'. That restriction is for trunks only though, subscriber functionality is unaffected.
If this STMI has been used for something else you might have some config in CGWB that will cause you a problem, I would consider a delete and re-add or change-cgwb with an initcgw to default everything.
Pay attention to the number format being sent to CUCM. If you test it and it doesn't work, take a Wireshark trace... If there is no invite, it's likely WBM config. If the invite is there but the numbering is wrong, it's 4K LCR.