1) The Church leadership (diocesan, national and papal) gets about 10% from the regular parochial collection. The rest goes to the parish.
2) If your parish doesn’t collect enough, it will close. If all good Catholics — those who seek out the best parishes — stop tithing, the best parishes will close while the worst ones will remain standing.
3) Religious orders do not, I believe, tithe up, except to the rest of their congregation. There are plenty (at least hundreds) of faithful religious orders/groups worldwide, like Priests for Life, the Fraternity of St. Peter, the Society of Our Lady of the Most Holy Trinity (SOLT).