Sorry, haven't been checking forums, I've been too occupied "playing" the game. Medic is 48 now, will get 50 tomorrow morning. To answer your questions, which you probably already have the answers to by now, the daily log-in is a reward you get for each consecutive day that you log on. It resets at 12:00 CET on the EU servers (So mid-day, this is also the same time daily quests/lockouts reset) and it gives boosts, omnibits, cosmetic rewards, mounts, pets, all sorts of cool stuff. They are account bound so you can claim them on any character, but you can only claim them once, so make sure you claim them on the correct character. As far as I'm aware, there is no time-limit on this, and as long as you claim the daily reward to your account, then you can claim it on a character from your account inventory at any time.
In terms of paths, it doesn't matter what class you play. Your path is intended to compliment how you like to play MMOs. It's a separate leveling system that you gain XP for by doing Path Missions.I'm a Scientist on my Medic at the moment, which gives you lots of lore information and also buffs from stuff that you scan with your scan-bot, and other cool stuff like hidden shortcuts that you can discover. Explorers get access to jumping puzzles and hidden areas and also gain XP from exploring the whole map etc. Soldiers have a lot of killing missions, such as assassination missions to kill a named mob, they get experimental weapons to use as part of their path missions, and also holdouts at certain areas. Finally, Settlers can create buff stations at quest hubs that everybody can use, they can work with other settlers or even just solo themselves to finish Settler projects which are in certain zones which give access to various cool things like bonus quests, special vendors, zone-wide buffs etc.
And finally they're still working hard to address the lag issues. Today has actually been a big improvement over the other days, and they seemed to have just recently (within the last couple of hours) finally found a fix for the character loop issue (where you were stuck on loading screen and then kicked back to character screen over and over). I was able to play completely lag-free between 8am-1pm today, and then was also able to play lag free from about 3pm-7pm until the loop-bug occurred again, then when they finally released that fix for the loop bug, I've just been playing now for an hour without any lag.
All-in-all, disregarding the server issues, I've really enjoyed picking up Wildstar again. The changes and improvements they have made felt like a completely new game and really bought me back in on a good light. I've already re-subscribed and providing the server issues are fixed within the next week or two, I intend to keep it going.