First, I want to address the issue you raise about "how could a celibate priest be a bishop", etc.

Apparently you are not aware that of the 23 rites in the Roman Catholic Church, 22 of the 23 allow married clergy as the norm... and in the Latin rite (the only one in which celibacy is the norm) there are exceptions made. In the Eastern Orthodox, married clergy is also the norm.

In scripture, Paul (who was single/celibate at the time) said specifically that he thought it was better for a minister to be like him due to the demands of ministry-- even going so far as to refer to his celibacy as a "charism" or spiritual gift (I Corinthians 7:7). So clearly, celibacy is an acceptable (even desirable at times) option for ministers--otherwise both Paul and even Jesus himself would be disqualified.

Second, as to bishops and priest being pastors... In the sacramental churches, this is exactly the way it is viewed. Bishops serve in the same kind of governmental/authority role as the apostles in overseeing the church-- "pastoring" not just a single congregation but the church in an area. Presbyters serve as "assistant pastors", assigned to specific churches under the bishop-- pastoring that specific church. The administration of sacraments is just one part of that pastoral role.

Finally, Catholic theology does teach that all believers have access to God. It simply teaches that different believers have different gifts and callings... and that a believer is not an "island to themselves" in his/her Christian journey, but rather we all need each other and the gifts/callings present in the whole Body. As Paul wrote "are all apostles? Are all prophets?..." This is just after a lengthy dissertation that there are different gifts and callings but that we are all part of one Body. (I Corinthians 12)

Just look at the people recognized as "saints". Yes, all believers are saints although in the sacramental churches those whose life of faith was so above reproach that their life and ministry is held up as an example to follow (as Paul said "follow me as I follow Christ"). Those so recognized come from all walks of life-- with the majority of them NOT clergy, but rather laity who were mightily used of God.