Need help with negitive total slack and conflicts

[DGriffin]

I have read some of the posts and know how to find the scheduling conflicts by looking at the tasks with negative float. I also understand that this is driven by must start on and other constraints. I have removed all resources and added that info to a text field. I have cleared the resource leveling and recalculated. My issue is that a number of tasks where if they are linked to the task above or not linked to anything and why scheduling as soon as possible it pushes it out over a year. For example linking a task to the task above should result in a 12/12/13 date but I get 5/14/13 date. I put a must start constraint on the task and then get a conflict error. I have a large plan with a number of over lapping tasks that contain a number of parallel processes. Is the issue that Project feels that there is no way that this much work can happen in one day? do I need to add multiple calendars? Please help me find a solution to have auto scheduling so I can see impact of dates that are miss and the impact of predecessors and not get errors.
Thank you

MS Project 2010