Configuring and using SIP Trunk with AsteriskNow

First of all I’ve read the post regarding Custom Providers.
But I think this is slightly different and that thread had started to go OT.
With the GUI it is possible to add a Custom VoIP entry in the Service Providers section. Looking at the changes to the .conf files after adding a new entry the only resulting change is to the users.conf file, nothing in the sip.conf file. This is what was added…

secret = 12345
provider =
trunkstyle = customvoip
username = 88888888
trunkname = Custom - voiptalk
callerid =
hasexten = no
hassip = yes
hasiax = no
registeriax =
registersip =
host =
dialformat = ${EXTEN:1}
context = default
group =
insecure =
fromuser =
fromdomain =

I’ve changed my real account info. The question is is this sufficient as far as Asterisk is concerned to configure a SIP trunk? How can you tell if the connection registers?

I’ve tried editing the Calling Rules section to enable _0xxxxxxxx numbers dialled to use this trunk but I don’t know what I’m doing so don’t know if I’ve entered it correctly. It doesn’t work.

If we find a way to start manually editing the conf files - is this going to cause conflict with the GUI configuration and break it?

I want to be able test things like BLF and call park/retrive. Will it still be nessecary to config hint for this to work??