I think there is actually a pretty simple answer to this. Now keep in mind, if you are truly Catholic, that our faith is a three-legged stool based on Scripture (written tradition), Oral Tradition passed on, and the Magisterium of the Church.
That said, we as Catholics are taught that what God revealed to us is his salvation plan. There is infinitely more to learn about God that he did not reveal.
Likewise, we are taught that Christ established his Church to aid us in our salvation. It is significantly easier to be saved by becoming a faithful member of Christ’s Church than not to be.
So the ordained, as the priestly members of Christ’s Church, are here as instruments of Christ to aid in our salvation. So in the examples you mention, two (reconciliation and consecration) are sacraments instituted by God to give us grace. Reconciliation offers us reconciliation with God and sanctification; the Eucharist is the source and summit of our faith, a necessity for salvation according to Christ. So priests must be able to perform these sacraments* in persona Christi*, as ways to get us to heaven.
On the other hand, raising the dead and healing the sick are not part of God’s salvation plan. Nor are other miracles you mention like curing lepers, etc. It is apparent by examining history that God permits these miracles to occur from time to time, per His will - we really do not know why or when He chooses. But they are not necessary for salvation. So that’s why priests cannot do them at will. He gives humans certain powers related to salvation in His name, He reveals certain things about himself related to His salvation plan. Nothing more. Get to heaven to find out the rest!
By the way, the name of our Church is the Catholic Church, not the Roman Catholic Church. If you are truly Catholic, you may not realize that RCC is a term developed by Protestants as a means to dilute the definition of Christ’s church, that it is “catholic” (meaning universal, all Christians) not “Catholic” (the specific church founded by Christ through the Apostles and their successors).
I hope this helps. I am a bit skeptical of your motivations, but I thouht a question deserved an answer. Everything I discussed here is in the Catechism of the Catholic Church, if you use the index you should be able to read a lot more detail about this explanation and see the Biblical and Early Church Fathers’ discussions on these topics by examining the footnotes, which are extensive. If you need clarification please ask, but I won’t be answering any more on this thread if it doesn’t look like you did your homework with the CCC.
Good luck and God bless!