1) Yes, it has a looot of romance! The family theme is a big part of the story, but don't worry, so is the romance! And you'll get to see each one of the brothers' love stories. There are like 2 main couples, but the focus is more on Gong Jun Soo and Na Do Hee's relationship and you'll be able to see their whole progression as a couple - from strangers to lovers. It takes a while before they finally start dating, but from the very first time they meet, they are so cute together and it's just fun to watch them even if they're in a relationship or not. I don't even know what I liked more - before they started dating or after - just because each one of those phases had its charms and I still believe they're the sweetest couple ever. The second main couple is also very cute and funny, mainly because they're totally opposites - you won't believe how much I rooted for them! xD
2) Well, there a lot of tragic moments, so I don't know how well you'll cope with that. I remember that were times when I asked myself how much more they can go through before they fall apart completely and I was so emotionally involved in the story that I could feel my heart breaking too! BUT each sad chapter ends well, and as much as you cry, you'll be even more happy when they finally overcome their hardships. I'm not into tragic stories either, but what I liked about this drama is that it keeps things balanced. I mean, things don't just go from bad to worse or there's always something bad happening - no, they are many enjoyable parts that will make you happy or even laugh, so don't worry that you'll get tired from all the sad stuff or anything like that.
3) This is one of this drama's strong points - it's not boring at all - and for a drama this long, this is really important! It has so many intense moments and there's always something exciting going on! And it doesn't drag on. I think the best way to describe this series is that it's a rollercoaster of emotions, so yeah, no time to be bored ;) I just kept watching episode after episode.
4) There are no love triangles. I mean, there's a man interested in the main female lead, but she just didn't care about him from the beginning all the way through the end, so I wouldn't really called it a love triangle since there was no chance for him anyway. This is another thing I really love at this drama - all the characters are so strong-willed and they always try to come to an understanding. And in the beginning, you'll see that each one of the characters has some kind of essential flaw, like how the main lead doesn't care about him at all and would always rather protect others rather than himself. Ok, this might be a good trait and I actually loved him for that, but in his case, it's way over the top. And liked that by the end of series, he finally started to think that it's okay to love yourself too. And each character slowly starts to learn to step out of their comfort zone and make a change.
And if you're still scared of the number of episodes, just don't even think about it and go now and see the first episode. You'll surely want to see the rest of them too ^^