Yes there is. One is infragistics>>NetAdvantage>>UltraGrid Control. It does all you want plus lots of other benefits. Try the trial

search notepad++ in sourceforge.net, it may help

There are some articles in this site that will read from an autocad file. Does files are vector drawings too and saved as ASCII text. DGN may be like that too. search for the article.

1. I don't know 2. If your property datatype is a structure, or class then the property will appeare like location(x,y) as you mentioned with the "+" sign in property window. What you should do is to use .NET's structures and classes ( as location is a "point" datatype I guess) or define new structures/classes as nested datatypes in your code and use them. 3.as I mentioned in 2, .Net uses system.drawings.color (I guess) for colors. If you simply set this class as the datatype for your property, then the colorpicker will appear in property window.

In DB you can design tree as the following: NodesTable(NodeID,NodeName,NodeParrent) NodeTable.NodeParrent 1===M NodeTable.NodeID and in ASP.NET use an DataReader to read all records of the table one by one and add them to the Tree datastructure you've designed.