Hi, gem5.

Allow me to step in and share some insights regarding downloading and managing your Stripe transactions in QuickBooks Online.

To answer your first question, to be able to download your data from Stripe into QuickBooks Online, I'd suggest getting in touch with the Stripe Support.

They can provide you all the data you need as long as the file is supported with QuickBooks Online. You can go through this article for more information: Import bank transactions using Excel CSV files.

For your second question, uploading historical transactions will not create duplicates. You can Match similar transactions or entries that have the same information in QuickBooks Online. If there's no existing entry, you can click on Add. This way it'll be added to your chart of accounts. 

However, if you see duplicate transactions, you have the option to exclude and delete them. You can still follow the process you used for your PayPal transactions.

You can find more information about these processes in the following write-ups below:

Categorise and match online bank transactions in QuickBooks Online

Exclude expenses from downloaded bank transactions

Don't hesitate to add a comment if you need anything else. I'll be around to provide additional assistance. Have a good one.