Yes, this program is designed for engineering students only. Although, the stipend will be paid from a different funding source, the same restrictions and deadlines apply. This all depends on the project and the department of your choice.
Some projects strike a better interest with some students than others.
It's encouraged that students meet with the professor prior to applying to understand the professor's expectations and requirements. Visit the professors during their office hours. You can apply for more than one position, but commit yourself to only one project. Be fair to yourself and to the professor. On the student application form, you may mark the Fall and Spring box to let the faculty know your interest and intentions.