Would like to make this a permanent migration and ultimately close the AOL account.
A few questions:
1) I see there are 2 choices- 'Import mail and contacts' and 'Check from other accounts'. What is the difference?
"Import mail and contacts" should actually import all your currently saved mail messages and contacts in your AOL account into your Gmail account that one time you run it. You count then kill the AOL account and start using the Gmail account.
"Check from other accounts" is basically just turning Gmail into a glorified POP3 email client for your other email account (basically making like Outlook or Thunderbird...just online). With this option, it is actually connecting to the AOL servers to retrieve new email. This option would require the AOL account to remain open.
2) Is the forwarding time limited (and reliable..as in does in do a complete job)?
I am not familiar with AOL's forwarding options, so I don't have specific answers. I do know that for many email services you can forward for as long as you want. As to reliability, at a minimum you will now potentially have each message being run through spam systems...one on AOL and one on Gmail. Thus, you might end up having more messages not make it through the spam systems, although it is possible that forwarding would bypass the AOL spam system (I just don't know). In my experience (with Comcast), forwarding works pretty reliably other than what the spam filter might catch (in my case, MobileMe/iCloud was the new email account).
3) I have about 50 AOL folders with saved mail (people, organizations, topics of interest, etc.. Can I create tis on gmail and how isit done?
Yes and kind of no. I say this because Gmail does not use folders in the traditional sense. It uses labels. Labels will effectively work like folders, but have the added advantage of being able to have more than one label for a message without having to copy that message (with a folder, if you want that message stored in multiple folders, then you would have to actually copy that message).
So, you can do what you want to do, but it technically is slightly different.
There are quirks to this difference, however.
Most of those quirks never really are an issue if you only access your Gmail account by way of a browser or an official Google Gmail app on say an Android phone/tablet or iPhone/iPad (such an app is in essence just a specialized browser to some degree for the one purpose of accessing your Gmail account). There might be a slight adjustment for you in such situations as it is a slightly different way to thinking of things, but online it operates very similar to how folders would operate.
The quirks are much more apparent when you access a Gmail account through an email client that uses a traditional folder system rather than labels in addition to also accessing it by browser or official Google Gmail app. Since I mainly use an email client and rarely access my Gmail accounts through the browser or Gmail app, I don't really notice those quirks.
4) Is there any auto way to notify contacts of change or must I do it manually (hundreds)?
Not that I am aware of in Gmail other than to do a mass email using BCC to large groups of your contacts or all of them. And even that method might run afoul of spam filtering.
The best option that I can think of is to setup a vacation notice on AOL (assuming it supports that...I don't use AOL, so I don't know) that basically says "I have changed email addresses. Here is my new email address: <youremail>@gmail.com. Please contact me at the new email address." This, of course, would require you keeping your AOL account open. You could then also setup Gmail to access your AOL account (see item 1) and if you wanted also personally reply to those people in addition to the vacation message...if you wanted...and if it is an email from a business/website, it would be the reminder to go to that site and update your email.
5) Noticed that mail is imported to the inbox AND to the sub category with my AOL address. Is this duplication normal?
See response to #3. This is the labels at work. The inbox, just like any "folder", is just a label. So, when you "move" the message to another "folder" in Gmail, you are effectively just removing the "inbox" label and adding the new label for the new "folder".
If you "delete" the message from the Inbox, you are actually effectively just removing the "inbox" label and adding a "trash" label if memory serves. You will still find the message in All Mail. Note: I could be incorrectly recalling this...my situation is complicated by that face that I have IMAP access setup and mainly access my Gmail account using IMAP through email clients on my devices. This kind of messes up Gmails normal ways of working if I recall correctly.
The ultimate point is that in your case, the message is being assigned two labels when being imported..."inbox" and "AOL account" (or whatever label it is assigning for that AOL address). It is still actually only one message on Google's server, but "appears" to be two because you are thinking in terms of folder, which Gmail does not use. Of course, if you then accessed that Gmail account by way of an email client on your computer (say Outlook), then it would actually be two messages...one in the "Inbox" folder and one in "AOL account" folder as that client would actually be using folders.
6) Last, imported contacts. Was interrupted. Did it again, So it's duplicated but won't recognize it as such. Any suggestions?
Thanks for any help and your patience.
As long as you have all your contacts still in AOL, then the best thing I can think of off the top of my head is to nuke all the contacts in your Gmail account and then re-import them again to the now empty contact list in Gmail.