My question is three fold: how could one possibly perform all of these;
It would be difficult if not impossible to do them ALL, and even if someone spent 24 hours a day just repeating prayers and got them all done, they probably wouldn’t be done very well.
God would rather you do 2 of them well than 2000 of them poorly.
are we expected to perform all;
No.
You aren’t “expected” to perform any. You are expected to pray to God regularly, which you could do by simply talking to God in your own words every day, or reading Scripture, without practicing any devotions.
and why would Mother Mary and Our Lord Jesus give us so many different ones?
Because different ones speak to different people. And different ones might appeal to the same person at different times in his or her life.
God likes variety in all things, and it’s reasonable to assume that extends to a variety of prayer forms.
Also, religious orders all have different charisms. They don’t all try to do all the things the other orders are doing. Some of them emphasize caring for the poor. Some focus on adoring the Blessed Sacrament. Some teach the young. Some of them are dedicated to contemplative prayer. Some of them concentrate on honoring Mother Mary. Etc.
You’re supposed to pick a couple of devotions you think are particularly useful or appealing to you and do them regularly. If your prayer life gets stale, it might be time to stop doing a devotion you usually do, and switch to a different one for a while.
Also, some devotions usually only last for a set period of time, like 9 days, or 1 month, unless you decide you like a particular novena and want to do it every day in perpetuity. The St. Bridget prayers last only 1 year in the case of the 12-month version, and only 15 years in the case of the 15-year version.
Think of devotions as like a grocery store. Do you buy and eat one of every food in the store every time you go? Or do you pick out things that look good to you (while the guy behind you may have picked out all different things that look good to him), only get as much as you can reasonably cook and eat before it spoils, and then eat those things, and on your next trip maybe you buy some of the same stuff because you like it or it’s nutritious for your body, but you also buy some different things? Same with devotions.