Is it possible to have a form with multiple fields but make only few visible on a given landing page. In order words, I am trying to use one form with 25 fields but make visible only 5 on Landing Page 1 and 12 on Landing Page 2.
No and Yes. 
Not out-of-the-box, but it's something we've done a few times, trying to emulate the "optional module" style in emails.
There are 2 ways to do it, both requiring JS:
- All 25 fields are marked not required in Form Editor (this is important). Use CSS to show only the fields you want (more precisely, the form rows that contain the fields). The non-shown fields will not cause validation errors b/c they are not required. Then re-add the same validation rules as custom JS onValidate rules.
- Pre-load and filter the form descriptor so only the desired fields are ever rendered. This is the advanced method, and does allow validation to stay in Form Editor. It's much more elegant in the end but more complex to build.
On a similar note, is it possible to disable some progressive fields of a form on a specific Landing Page and keep active on an another.
Same answer as above really. You can supplement progressive profiling with JS + use CSS for the show/hide logic. Just the other day I was rolling my own ProgPro, b/c the client wanted irregular ProgPro blocks (2 fields, then 1, then 3, etc. which doesn't work w/native ProgPro). Of course the native feature is plenty cool, but you can outgrow it just by spec'ing out other cool things...
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