Wish I had a more definitive answer for you... but I don't! I know that some of the intermittent errors you experienced, like the "obsolete transaction" error were a temporary glitch due to some changes associated with the HardFork taking place over the next few days.

Are you able to access hive.blog at all on your desktop? For example can you see your settings options but not any blog content? If that's the case then you might try switching the node/API endpoint in the advanced settings.

If the entire page is throwing an error which I assume is the case, it almost seems like it would have to be browser related? Have you tried clearing your browser cache/cookies etc? Those may not be "cleansed" by a restart of the computer itself.

I am primarily a PeakD user myself, but hive.blog seems to be fine on my end. When it comes to Hivesigner I think the most common error some users make is trying to put in their public key and not their private key, so perhaps double check that for your troubles there. Overall I mainly use the Hive Keychain plugin whenever possible instead of Hivesigner. It's always seemed smoother and more user friendly for me, so it would be another option to look at if you want to get up and running on PeakD or other Hive based sites in general.

Lastly, if you have a self hosted Wordpress blog are you aware of the Steempress plugin? As far as I know it hasn't been renamed yet... but it's a plugin that did make the changeover from Steem to Hive earlier this year. It allows you to post to Hive direct from your Wordpress blog, integrate Hive comments on your wordpress blog if you choose, etc. Well worth the look if you haven't seen it before.