The fx glyph indicates that an Expression exists on the item in reference. The first picture indicates there is a an expression on the Precedent Constraint between two items. Whether they're backed by Variables or hard coded won't be known until you explore.
The blue color I think is that the preceding task must finish (Completion) - failure or success does not matter. The red dashed line coming in from offscreen is the Error/Failure path from a Task.
The Dashed line indicates that there is a Logical OR condition between all the elements that feed into the icon offscreen. A solid line will indicate a Logical AND condition.
Double click the blue precedent constraint and you'll see something like this
You can also right click on anything and select properties. An element like a Precedent Constraint will look like this
More complex tasks will have the Expressions in their own section i.e.
All that said, you should be able to add the package to an existing SSIS project and Visual Studio will upgrade it to the current revision. There can be hiccups with things like script components which are usually resolvable by opening up the script and rebuilding. Other things, like custom third party components, need to be updated to bind to the current version of SQL Server binaries.