Flickr is a great option, but I understand your hesitancy with the SmugMug acquisition. I'm under the impression that Flickr is likely going to stay free too some extent, but you really do never know. Here is a more info (and an interesting read) on the acquisition from the CEO himself:
https://www.reddit.com/r/photography/co ... h=187436d4.
If you are looking for a storage solution, you may consider an external hard drive or something like Backblaze cloud based storage and file management system. If you are looking for a solution to embed photos in to forum posts, Flickr and Imgur are great options. If you are looking for a hybrid of the two that's free, Flickr is one of the better solutions. SmugMug is more-so targeted at photographers who host galleries for clients to download and print from. From what I understand, that's really not what you're looking for. If I were in your shoes, I'd invest in some sort of external hard drive or cloud based drive, cherry pick the photos you want to upload for a particular post, then upload those to Flickr. In a perfect world, our favorite fly fishing websites like this would have their own hosting/image upload system...but sadly most do not. It's kind of a crap-shoot wether or not the hosts will be around in 10 years. At least with an external back-up, you will always have your original photos in a safe place and can upload them again if one of the hosts was to disappear or go down.
DISCLAIMER: This may be long winded. I'm a full time photographer and deal with this every single day. File management and back up is critical for the work I do. I DO INDEED use hosting solutions like SmugMug, Pixieset, etc. to deliver galleries to clients. However, all of my work is also cataloged on external hard drives and in the cloud for redundancy in case something did crash. From there, I can publish directly to my own website via my own hosting, or if I want to post on a forum like FFR, I can easily cherry pick the photo(s) I want, upload to Flickr, and easily get an embed link.
Hope this helps!
-Chase