I wouldn't want to store btc anywhere online.

What's meant by the "blockchain loading up"?

How I am I supposed to know about encrypting wallets, backing up dat files etc.

I'd thought that these were relatively simple questions I'd asked in my first post, and had hoped for relatively straightforward solutions. At this rate it's going to be many years before btc gets anywhere remotely near to mainstream acceptance. Not a reflection on the person who replied, but this reply has swayed me slightly more towards deciding against btc than I was before.