Look up function, just add new entries OR Subform size definition

Hey there, I just want to use my original inquiry form with a look up field to my address database, to send it to my contacts, that they could type in there inquiries by there own. Why ever there isn't such a function in Zoho Creator, where you could set up a adjusted kind of your original form for the public use. Of cause you could create a second adjusted form, but then it‘s very annoying to add this selected data to your old main view....

So I scripted a little code, which indicates if a stranger is using my form (i.e. on my website or with direct links).

So far so good. It is easy to hide some fields with this script... BUT the lookup field is such a big problem. As I said, there is a relation ship to the address database. It‘s easy to deactivate this field, but the user have to input there respective address data to the entry.

So I thought I could solve that problem with a subform which just is shown, if somebody is indicated as a stranger.

But there is a problem with the subform, compare the attached screenshot. There are too many fields in the childform, that just blast the whole form.

1. Is there a possibility to adjust the size of the Subform (iframe or something)

2. If not, and thats what I prefer, is there a possibility to deactivate the look up function from the look up field, but let the "add new entry" function untouched (with a pop up)?

THANKS!!!!!!