Yes, it is possible to indirectly edit the columns of the joined table and have the changes reflected through the ArcMap join.

--Add the joined table to ArcMap and perform edits directly on the table's data.

Changes will be reflected in the joined columns and refreshed whenever ArcMap reads the table, such as opening or activating the joined table. A benefit to this approach is that schema changes made to the joined table will also be reflected in the join.

--Edit the joined table in another software application.

Edits can be made to the joined table using Access or other applications. Changes made to the joined table in Access while it is open in ArcMap are cached and it is necessary to refresh the table in ArcMap to see the changes. If one of the joined fields is being used as a Label Field, it is necessary to refresh the map by clicking the Refresh Map button in the lower left corner of the map display window to see the updated labels.

ArcGIS has a different underlying spatial grid from Arcview 3.x. ArcGIS uses an integer grid while Arcview 3.x uses double precision. This difference causes the shapefiles created from the results of a clip on the same dataset to be of a different accuracy in the different applications.

The Zipper Task is an ArcObjects Developer sample that can be used to help close gaps between polygons in a feature class. How to install and use this tool can be found in the ArcObjects Developers Help under the Contents tab > Samples > Editing > Edit Tasks > Zipper Task.

The Auto Complete Polygon task uses only the features in the current visible extent.

To workaround this pan or zoom in the map so that all polygons that are adjacent to the intended polygon are visible. The Auto Complete Polygon task will now create the new feature.

No. ArcGIS does not provide the ability to modify the extent of shapefiles and/or feature classes once they have been created. To change the spatial extent of a dataset create a new dataset with the desired extent and copy all features to the dataset.

No. Adjacent polygons cannot be merged by deleting the shared topology edge between them. Navigate to Editor > Merge in the Editor Toolbar to merge adjacent polygons.

The default number of allowable Undo operations for a geodatabase is 30. After 30 consectutive Undo operations, the Undo button will become disabled. This limitation cannot be changed for a personal geodatabase because it is a limit imposed by the Microsoft Access format.

The table window in ArcMap includes commands to add or delete fields from a table. These commands are greyed out. This occurs because fields can't be added or deleted during an edit session. To workaround this stop the edit session and then add or delete fields.

This differs from ArcView GIS 3.x, in which you must first be in an edit session before you can add or delete a field.

It is not possible to change field display order for a table permanently within ArcGIS. Changes made in regards to field order can be saved within a particular Map Document. This behavior is common across the various supported data types.

When a new field is added to a table in ArcGIS, the field will be appended to the last field on the right hand side of the table.