Regarding Google+ data takeout....
I definitely will perform G+ data takeout but the earliest would be in January, and I'll do it once every 3 months until the closing date. I hope it's possible to do that because it would be a really bad design on Google's part if they only allow it once. I've heard we need to choose either HTML or JSON format. JSON would be preferable as it has better compatibility with future import tools but having a HTML version wouldn't hurt either. Why? Keep reading.
I have no plan to reuse the data even if I there's an import tool being implemented here or elsewhere. If I have the HTML version of my G+ data I could theoretically load it into my browser for viewing without having to perform any modification. I've run blogs before and in 10 years time I've switched my hosting at least 3 times. Every time I switch host I always start from scratch again and for me it's fine as long as I keep the same domain (usually only the TLD changed though). I still load the data into a locally hosted WordPress to look again at my old blog posts for reference. I think I'm going to do the same for my G+ data. I just think it's easier to start all over again. After all I came to G+ in 2011 without knowing anybody there but I managed to build my connections pretty quickly. In a month I managed to connect with almost 1000 people there.