I'm size 8-10 and struggle with items like running belts and have to cinch them in to their maximum and sometimes it's not snug enough. At least my B cups aren't too problematic. Most of my "small" race t-shirts are voluminous and I have several that are ginormous because the race ran out of smalls. Last year I did a 10k in 27oC and very humid conditions with a double steep hill. I thought my 1hr 10 was rather respectable in those conditions, but only XL was left (no medal either) a shame I was left with a saggy knee and elbow length dress as it was a rather nice design.
The biggest annoyance is pre-race toilet queues. A lot of local races are based from a sports stadium. The men's queues barely sneak out of the toilet area. You can barely move around the venue because of the long trails of women queuing. I barely get chance to do the warm-ups because that's the toilet queue time zone.
Cut off times do have the practical element of safely managing road closures and the well being of marshalls in exposed heat/ cold/ wet for many hours and you need sufficient marshalls to provide support. Some races will be more inclusive of slow (female) runners than others, I have no issue with that. As a pretty averagely paced 35-40 year old, in big, charitable races I'm mid-field, at smaller club races, I'm towards the rear, but I'll always check that I have a good margin avaliable. What was wrong was this year's VLM where the 7:30 pacer group was hounded by the clean-up operation and the miscalculation of cleaning up on gun time, not the start time of the final wave who started around the time the professionals were finishing.
The other thing is race numbers are too big to fit between my bust and waist. Where I can, I try to fold the sponsors' logos underneath to reduce the area.