A partial list of examples of institutionalized spiritual abuse would include an institution and its leaders controlling, manipulating and/or dominating the sheep, rather than encouraging the sheep in their free will. Telling people what to do and/or over-confidently insisting that they are speaking for God as in "thus sayeth the Lord". Institutionalized lies which benefit the institution such as telling people that they have to attend an institution and/or make an institution their home church, and/or give 10% of their paychecks to an institution or they will be displeasing to God, or they can't be blessed, or worse that they will be cursed, etc. Leaders of institutions Lording themselves over the sheep rather than treating them as equals. Making their institution and its leaders a substitute Lord for Jesus. Making demands upon the sheep to attend the institution on a regular basis and guilting, shaming, condemning and/or cursing the sheep when this is not to the abusers satisfaction. Placing unreasonable expectations upon the sheep. Stepping deep into the personal lives of the sheep including as one example forbidding them to marry or forbidding them to leave the institution without cursing them. Bullying, intimidating, threatening.
I don't know if you watched the excellent video i linked in this thread above, but this too provides the video maker's own personal story of how she was spiritually abused by her wolf in sheep's clothing pastor.
You had said, "My answer to that is one must have a personal relationship with God which comes from the heart." and i completely agree with this.
You also said, "to need a pastor or group etc. to become spiritual with God is not possible because if you use that source then you as a believer are thwarted by know-all bullies." It's so true that everybody needs to meet God in living relationship for themselves. I do believe that those with more experience can and do help those with less experience towards this and that this is of God, but each individual must guard their heart against becoming spiritually abusive including Lording themselves over anybody. This is most especially true when they have been given a position of leadership within an institution because the temptation and the opportunity to become puffed up, controlling and dominating becomes extra strong.