Changing behavior of lookup suggestion/autocomplete

Changing behavior of lookup suggestion/autocomplete

Hi,

1-I'd like my lookup fields not to display records in a dropdown fashion. The info in these lookups are private and I'd like the user to type in his value (for example, email), and after 3-5 letters the field would start searching for autocomplete.

2-Or another solution would be to not give any autocomplete/suggestions: to just match the value with the existing record, and if there's no match, then prompt the "Add new record". 

3-The last solution would be to filter the lookup in a way that no suggestions appear, only "Add new record". The issue here is that during record creation, if it finds a duplicate value (ex: mail, which is Unique), then it does not allow to create the new record. Is it possible to change this behavior so that if a duplicate record has been found, it links it directly to the main form's lookup field?

Any of these things are possible? (I'd much prefer solution 1 or 2)

Thank you!