This is a nice collection of completely false statements used for ages by opponents. Much of it sounds like it came from fiction authors like Dan Brown (of the DaVinci Code) which is where I assume you got much of this.

• The Council of Nicaea did not have such an agenda. Subsequent councils discussed this. They looked at all the texts in use by over 300 bishops surrounding the Mediterranean and applied this simple criteria: Did each document have apostolic authority? i.e. could it be traced back to certain authorship by an actual apostle (Paul, Matthew, Peter, John, James, Jude) or one of their assistants (e.g. Luke or Mark). So this was not "engineering" it was due diligence. None of the texts were changed in the process and there were many copies available for cross-checking errors.
• All Biblical Christianity teaches that God as the Holy Spirit dwells within us as Jesus explained to Nicodemus in John 3. So this was not suppressed, it is the fully accepted teaching of Jesus himself.
• Jesus hand picked those disciples and instructed them to go make other disciples recursively. They did that for a few decades and in the process wrote letters to other cities which were treasured, preserved , and proliferated while the authors were still alive. Only a few of them were written intentionally as historical accounts. Jesus told them that the Holy Spirit would ensure that they remembered everything He said to him and taught them in the 3.5 years they were his daily traveling companions. Peter and Paul both declared that Scripture was written by God as the authors were "carried along by the Holy Spirit." Jesus declared that Scripture could not be broken and should be believed down to the last "jot and tittle" punctuation and the tense of every verb.
• We have 5600 manuscripts dating as far back as the first generation of contemporaries of these authors so there is massive redundancy. They all agree except for minor "typos" easily corrected by comparing them with each other. So we know exactly what the original authors said in the original Greek. All translations go back to this original source so there is no compounding of errors at all.

There is simply no historical document of any kind that has a more pristine pedigree than the Bible. If you won't trust it, you can't do history because you have to throw out 100% of all historical records of any kind.