Fresh install 7.8.2 after using SugarCRM 6.4 - problems or just differences?

I have recently installed SuiteCRM Version 7.8.2
Sugar Version 6.5.24 (Build 509)

I did a fresh install rather than upgrade and migrate thinking it would be better (cleaner)
After spending many hours importing my contacts and leads etc from my old Sugar CRM version, I am having some ‘problems’ which I am not sure if may just be differences?
e.g. After replying to an email or ‘relating’ it to a contact/lead in Suite, the email still shows in the inbox.
In Sugar, once you reply or ‘relate’ it, the email disappears from the inbox.
The latter is obviously better, otherwise the inbox is going to get massive!

Can anyone tell me if the behaviour I am seeing is an issue or just a difference i.e. how Suite is supposed to work.

Also the ‘search’ function does not seem to work properly e.g. If I put an email address in the ‘search’ box in Sugar and it is listed, it shows only the ‘Contact’ or ‘lead’ with that email and the 'contact’s and ‘leads’ lists are separated, so it is easy to see if the person is a lead/contact etc.
In Suite, when I put the same email address in the ‘search’ box, I get 20+ entries showing in addition to the one belonging to the email address entered and the leads and contacts are all mixed up i.e. a couple of leads listed, then a contact, then a lead, then 2 contacts. This makes no sense to me at all.

Are these ‘issues’ I am encountering actually issues, or is this how Suite is supposed to work?

Many thanks in advance!