Hi @Jesmion, when posting in the community, you should be able to edit any messages by clicking on the Options button at the top right side of your text. Once there, click on Edit Reply/Edit Message:
This will open a window that will allow you to edit your text, add/remove images, links, etc.
In regards to your profile picture, editing your posts should not interfere with this setting. To add a profile picture, open your community profile and click on the top of your current image.
I hope this helps!