Copy and paste the YT link from the address bar and the site usually embeds it for you. Although sometimes I have to do it twice.
Just paste the link without giving it a title.
Like @NancyJohnson says, pictures are required, preferably in a NBD* topic just for that purpose. You'll enjoy having both options, four or five strings, I am sure.
*New Bass Day
Basschat has a section for Feedback on member transactions.
You can search the section by member name and get an idea of their reputation with dealings on site. It's good form to let people know how deals go afterwards for that reason. Here is a link to Oldman's Feedback.
Glad to hear you are getting set up again. I wish you a lot of fun with it.