List of trainings available for Workfront ?

using VEC based eitor - > No you cannot May be it is feasible using form based activites, provided your implementation is inline with this approach.

As long as enough product data with the criteria is there you should not see any issues. If your collection is just formed with 2 or 3 products in it , then there is a chance of this issue.

you mean moving between profile (workspaces) with in Target ? For target. , always maintain 1 to 1 mapping from AEM to Target , else it will create an issue. 

if you dont give category , it will end up in recommend any product.Also wondering how you manage to create a collection , without a category id. 

write a profile script , so that when ever user comes for the first timeadd an attribute abc=true then on whenever user visits the site , if the attribute is present then show the banner  

curl -X POST --data-binary @BATCH.TXT http://CLIENTCODE.tt.omtrdc.net/m2/ CLIENTCODE/v2/profile/batchUpdate 

If you store it via js code , then you can store it in the browser.Con: It will be flushed when user deletes the cookies..etc   If you use profile script , you can maintain the counter in the server side (at the target server side). This is the right way for capture such data.

Not sure whether you have framed the question properly. Each Target userID will have tntID , which you can capture on the delivery call

Adobe Analytics:1) Can have a segment based on user historic behaviour2) Not a near real time3) When you create the audience for the first time , it gonna take atleast 12 hrs sometime more to reach target4) I think there is a limit on number of audiences i.e. pushed to AT via People service.5) If so...