just making sure they can't recreate my deleted posts and comments even in a disassociated state after they delete my account.
Reddit Migration@kbin.social – 0 points – 
I found a plug-in for Firefox that deletes all posts and comments from your reddit account. (Power Delete Suite). Now I am in talks with reddit, to have them delete my account and data.
They say that all content will be disassociated when I delete my account but I had them confirm that they won't recreate it when I have deleted it. They still say that they will retain the IP used for creating the account. Not sure if this is legitimate data redemption after I have asked for my data to be deleted according to GDPR?
Be careful here, these tools don't always delete everything, see https://kbin.social/m/RedditMigration/t/47320/PSA-If-you-have-more-than-1000-posts-more-than
A better way is to make a GDPR request for your data and then use something like shreddit to delete it. If you can't wait, then you can also try the process described in https://kbin.social/m/RedditMigration/t/65260/PSA-Here-s-exactly-what-to-do-if-you-hit-the
Important to retain this!
Only if they can find some other basis to keep it now that you've withdrawn your consent - e.g. some law in an EU member requires them to retain the IP address. Another example - they claim they need it in much the same way that the credit card money needs to know your personal info so they can continue collecting your payments until the debt you own them is paid off.
TBH, I'm hard pressed to understand on what alternative basis they are able to use to retain your IP address. This might be something to refer to your regulator for additional information.