With regards the guardian site relogging.
It could have been solved using a method they already have in game.
When you try to scan a datapoint you've already recently scanned, even after relogging in many instances, (In fact, in some cases, for days afterwards) it simply says "Data point already scanned" part way through scanning them.
This'd mean you'd need to move to various different sites to gain more blueprints.
If I worked for FDev I'd be seriously reluctant to implement something like this when there's no way for somebody to actually set about finding the sites using in-game tools.
You are, basically, saying that these things should just be mega-rare random drops which a player has a one-in-a-million chance of finding and they should be okay with that.
When there's an in-game lexicon that is updated in real-time, as players make discoveries (in much the same way the galmap is when players make new discoveries), then sure. Have at it.
With that in place, players will (presumably) be able to use the lexicon to find the locations of every known Guardian site and travel to them to collect stuff.
Also, to be completely clear, updating the lexicon every couple of months, or whatever, won't cut it.
It MUST be updated in real-time, exactly as the galmap is, in order to remove the need for 3rd-party sites, so that FDev can assert that it's reasonable to expect players to be able to locate stuff.