The play 7k comment was partly a joke. That said, 7k can be a LOT of fun once you learn it. Also, even at 2 stars, you cant just compare star rating between 2 maps, because the different mapping style between maps can make a huge difference in difficulty. A 2 star map that features mostly LNs (long notes, aka sliders or holds) can easily be harder to score on than a 3 star map with no LNs and easy patterns. And it only gets worse as you get higher in sr. I still fail some maps in the mid 5 stars in 7k, but there are also a few maps over 7 and 8 stars I can pass.
Star rating is calculated by looking at the density of notes in a map, but it knows absolutely nothing about what patterns are easy or hard.
Its best to look at star rating as a very rough guide. Dont worry too much if a map is within 0.5 stars or so of what you usually play. If you like it, try it. If its too hard, then come back later, but don't just ignore maps because the star rating is a bit higher than you think you can play.