Panel 2: "You're gonna love it." Sigh. Never say that to a 14 y/o.
Panel 3: Well, no, not necessarily. Mike didn't want to leave Martha, and their relationship almost derailed when she didn't answer his letters. Liz had a pretty good time, but on her return, she found that her friends had moved on without her. No, I'm not saying that there's nothing to be gained from a summer on The Farm, but at 14 (and I think Mike and Liz were a year older when they had their summers) things matter in a way they didn't when you were younger.
Panel 4: Awww. Sweet young love. In the color version, the thought cloud is pink.
I dunno; I can't say my heart really breaks for her. Personally, I just don't like Gerald; I think April can do better. Maybe she'll meet a guy when she's out there. We never saw Mike or Liz interact with anyone their age except family, but that doesn't mean there can't be some good-looking teen guy whose dad owns the feed store or something. The summer I was sent to Camp Grandma, I met a guy, and he, and the summer, were awesome. So perhaps I should retract what I said earlier, because it might turn out that April won't miss out on everything by going away.