Cocoa butter is very stiff and rigid, and will feel the same even when whipped. Mango butter is dry feeling and crumbly and will feel that way when whipped. Shea butter can be quite crumbly and dry feeling when it is unrefined or less refined and greasier and slicker when refined or ultra refined. Get to know the skin feel of your oils and butters and you can kind of predict the finished product. (Check out the posts on this topic in the newbie section of the blog!)
And yes, I said you could re-melt it and whip it again! Anhydrous products can be re-melted and cooled again if we aren't completely pleased with the final product. (We can't reheat water based products because we could compromise the integrity of the preservative. We don't need to use preservatives in non-water containing products!) You don't need to heat it to boiling - melting it enough to be able to whip it will be enough!