Yep, lots of stars! Beyond the required
/* */ it's all a matter of preferred style. WP developers try to follow the inline documentation Docblock standard. Probably the only important factor is what ever style you choose, you use it consistently. This makes it easier to quickly reacquaint yourself with long forgotten code when you suddenly need to update it to remain compatible with some API or something.
Sure, changing CSS like that is just fine. It might change the page flow a bit, but if you don't like the result, you adjust. Whatever you like should be OK if it works. Your site, your rules :)
I did see your other question, I'll reply here if you don't mind. I'm hoping a lack of response on that thread might encourage someone else to join in on the conversation. Note that in your title you mention wp-content, which can be moved, as I mentioned previously. But in the text you ask about moving wp-admin. I don't know why one would move wp-admin, I don't think it's even possible, but I don't know this for sure. I'm going to assume you meant wp-content all along.
I think moving wp-content is fine if you have reason. If not, you could be asking for trouble if your theme or plugins are not using the proper functions to access wp-content resources. If everyone is following the rules, then you will not have any serious problems. Unless you've hardcoded paths in your own code :) All code should be using path functions that get information from the constants WP_CONTENT_DIR and WP_CONTENT_URL.
All the paths in post content can be a big issue. A different wp-content folder is best done on a fresh site. If not, you could let wp-content remain, and just start using a different content location. You are then only moving themes and plugins, not images and other resources. O you could create a rewrite rule to correct any requests for the old location. Or you can globally edit your DB to bring all the old paths up to date. Because some paths could be stored in serialized arrays, you should not do this unless you really know what you're doing. Fortunately, there is a tool meant for moving data to a new site that can be used to do this somewhat safely. Of course you backup everything before doing anything to your DB.
I'm unsure just how far you can move the folder, I believe anywhere on your server that's publicly accessible will work. I have moved the folder on one of my installations, but it's still at the same level, so any errant relative references will still work. There shouldn't be relative references though. So I've really only renamed the folder, not effectively moved it. There remains a wp-content folder that is not used.
Why? Probably the main reason the folder gets moved for anyone and possibly the reason moving was allowed in the first place. For Subversion version management. I can leave wp-content exactly as it is on the subversion server and still customize my installation. As far as Subversion is concerned, I haven't changed a thing. As far as the WordPress installation is concerned, it's highly customized.
But unless you want to run a bleeding edge installation matched to the core trunk files, the rationale to move diminishes quickly. Some people move or rename it to obfuscate the fact their site is based on WordPress, usually in a misguided attempt to deter hackers and spammers. A form of security by obscurity (an oxymoron).
Perhaps someone had an existing site and converted it to WordPress. They didn't want to alter their existing file structure and wanted WP to use some of the existing resources. That is a valid, though somewhat rare situation.
I'm not really thinking of any other reasons, valid or not, except for those in the "because I can" category. What's your reasoning? Or is this just a question from curiosity?