These criteria are very confusing and ambiguous:
Domestic or foreign Junior 18's ranked in top
150 nationally
This one is clear. If you had a ranking in the top 150 nationally in 18s, you're subject to this guidelines. There is no mention of sectional rankings for juniors here.
Domestic or foreign Adults ranked in the top 20
nationally or in a section in the top 10
This refers to ADULT rankings, not juniors (i.e. adult tournament rankings). It is not clear whether age group rankings apply or just Open (I assume NTRP ranking don't apply because that would be stupid, but it doesn't specifically SAY that they don't, either...).
Former Junior who had a national or sectional ( foreign or domestic) ranking but did not tour or play in college
This covers sectionally ranked juniors, but it doesn't say what rankings apply. A kid who has a ranking of 300 in this section is certainly not a 4.5, much less a 30 year old who was ranked 300 as a kid and then quit playing competitively for 10 years, so interpreting this to mean any ranking seems unduly punitive. OTOH, it doesn't specifically say "top 10" or "top 20" or "top 50" or whatever, either, so who knows?