Are there any who have High School aged and are doing Homeschool?
Most of the thread seems to be little kids thru Middle school.
The HS are few and far between.
We have had a varied homeschool experience including in and out of public schools as well as using virtual charter schools. My oldest wound up graduating from a public school after re-entering the system in the 8th grade. Our district at the time would not allow anyone in the advanced math track unless they had started it IN the district IN the 8th grade.

Oldest went there, then moved to my parents for better opportunities (AP courses, dual enrollment) and graduated there (although we all wished we'd skipped the commencement as it was a free-for-all nightmare). She went to college for a year, but really struggled (so much for the public school's "college preparatory" education

). She went to Disney with the College Program and wound up staying on. She's full time here and has recently gone back to school to work on her Associate's.
2nd DD returned to PS in the 8th grade (same reasons), but I wound up pulling her in 9th grade due to continued problems with the school. We used a virtual charter school which was a disaster (it was in its early years and hadn't worked out the glitches). We unschooled for awhile and she finally asked if she could just take the GED at 16yo and get on with her life. She did, did great, took the ACT and went to college at 17. She wound up doing the Disney College Program, too, and stayed on. Earlier this year, she went "seasonal" at Disney and moved to Colorado with her boyfriend (don't get me started on THAT one). She has debated returning to school, but she really isn't all that interested in any of it. She's very happy with her life and that's all I ask of any of my children.
3rd DD is entering 9th grade. She's not a fan of the curriculum we've been using (Oak Meadow), so I told her, as a summer project, to research curricula and see if she can find one she likes better. If I concur, we'll use that instead. We also tend to unschool more and use the curriculum loosely. We do use Teaching Textbooks for math and both DDs love it.
As far as the higher maths/sciences go, we will seek out the help we need as the time comes. If I have to find a tutor or a co-op or a local center with a class, that's what we do. Homeschoolers find ways to fill the gaps in the knowledge (or gaps in confidence) in order to fully educate our children. We also need to remember that not every child is cut out for college. Our society has long focused on college being the end-all and it is not. In our family, happiness is the end-all. Fulfillment, a good life, contentment are our goals. If we have "enough", it is enough (and that is going to be different for each person). My oldest, "enough" includes spendy trips to Whole Foods and expensive Disney restaurants. For my 2nd, "enough" is no debt and a solid emergency fund while still having time to go hiking or camping with her friends.
My children have seen positive benefits of a college education and know that we do value it, but don't prize it. I am currently in grad school (graduating in September

) and they see that my educational path has led me to a statused manager position at WDW. My Dad is also a college professor, so there is that example as well. Again, though, we let them decide their paths and do our best to provide them with ample opportunities to pursue wherever those paths may lead.
As far as the GED goes, I've said it before, but it has not been a hindrance in any way to my 21yo. Many schools are wising up that a "diploma" isn't worth the paper it is printed on and rely more on ACT and SAT scores (both of which were very good for my DDs) as indicators of future success in the university (although, again, not everyone is cut out for the college experience).
The world is SO much bigger than curriculum or schools allow it to be. My daughters amaze me every day with what they have learned simply by asking a question and following where it leads. 14yo and I recently had a long, quite mature discussion on Haiti and Chile and I learned that her heart is as big as the universe and it wouldn't surprise me to find her signing up soon with a volunteer organization that will carry her around the globe. Her "enough" seems to be a lot smaller than the rest of us in the family, so we are learning from HER as well.