Hi all, i'm new to the User Group, i hope i'm not asking the same question for the 100th time.

First, i have been struggling with project tools for 20 years and still do, they still don't work anywhere near as versatile and practical as real-life projects i participate in or lead (consulting business) so i revert to drawing coloured bars in Excel 95% of the time. Still, i can't stand to not master this gantt chart project modelling, so once in a while i make another attempt.

After finding out how to change tasks start dates (just put the % completed back to 0) , i have another gripe with Critical Paths. First of all, tasks appear red when they don't even have predecessors or successors. Also, removing a single short task related to nothing makes 20 other tasks go red in an instant, without these tasks even being related to eachother in some way.  So, i found out i can add the column 'Critical', but i cant check/uncheck most tasks as cricital.

How do i get control over the critical path? 

Thanks!