Wow -- a lot of questions. I'll answer some, but not all of them (I'll explain below).
Obviously, I don't think your age will be a factor at all (you'll be 35 -- a prime age group from which employers are eager to select from due to their life experiences).
Will it be hard to find a job -- that, my friend, is the million dollar question! I guarantee that there will be forestry and associated natural resource jobs available when you graduate -- landing such a job, of course, will be your responsibility!
Coursework will be coordinated with your academic advisor and your coursework will coincide with the degree requirements at your academic institution. You will have ample opportunity to take some electives, including geology and meteorology -- both are very valuable to a professional forester!
Don't use the BLS website; instead, use the federal government's OPM website for details and specifics regarding professional job series titles:
Forestry Technician Series 462:
Forestry Series 460:
All other questions: Please contact a local Pennsylvania DCNR forester and ask to meet with them and have a one-on-one discussion about all your other questions and concerns as Web-based dialogue is not an ideal venue for planning your future!
PA DCNR Bureau of Forestry: http://www.dcnr.state.pa.us/forestry/
Best of luck...and believe me, you won't regret your decision as I absolutely love being a professional forester!