Start off by eliminating Pitt and PennState as they sound unaffordable.
Next ask, what would your student be choosing if they had been accepted directly to the UMD Environmental Studies major?
Because as you describe it, the UMD option and the UDel option seem similar. Both require your student to jump over some bar in order for them to achieve their goal. UDel’s bar is that it requires a certain GPA or they pull the scholarship and the school won’t work financially. UMD’s bar is that it requires a certain GPA or your student can’t transfer to the major and will have to settle for some other major. Seems sort of equal to me, so I think your student should choose the one they like better.
My own opinion shouldn’t matter, but I’ll tell it to you anyway: I have a positive bias toward Applied Ag programs due to my experience with an Applied Ag department at a different university. I worked for a time in the Ag department of my state’s flagship and felt that it gave students a really good experience. It was one of the smaller programs at the University and gave students a lot of individualized attention, smaller class sizes, etc. The professors and the students were smart,hard working and down to earth. Also, a relative of mine was an Economics major in the department of Arts and Science (the biggest school within this flagship university.) Economics was his first choice major, and he was a good student, but he was having trouble passing the foreign language classes that were a requirement in the A&S dept. So he ended up transferring to the Applied Economics major within the Ag Department (which had no foreign language requirement.) Even though Ag applications of economics had not been on his radar previously, the program turned out to be a great fit, and even better there were a ton of jobs waiting for him when he graduated. He got hired by a global company that has afforded him lots of room for advancement. Turns out, this company had a long tradition of recruiting heavily from the Ag school, but not the A&S school. Apparently this company agreed that its graduates were smart, hard working and down to earth.