Hello Faruk,

I'm afraid that I don't have any bad news to give to you . Especially because the answer to your inquiries above is yes to all!

I was wondering would we have he option of switch from composer to other editors from frontend on easyblog 5?

Yes it can.

Would we have the option of adding custom html buttons?

Yes it can. You can use the HTML block from the composer.

would an embed iframe button be included in embeddables?

Yes you can. You can embed custom iframe using HTML block.

Hope these help