Problem:
Using a form or a content template in a widget
Solution:
The thing is that Toolset do not control the header, footer or sidebars. You can control few theme options of header, footer or sidebar if you are using integrated theme then you will see few theme options.
So, there are two ways, either you should create a content template where you should add a two column grid and add the from on one column and your desired content on another column.
The issue here was that the user was concerned with the difference with Views and Blocks and if views will be replaced by Blocks.
Solution:
Views and blocks are the same plugins. Which means whatever you can do in views you can do in Blocks. Blocks also has the views classic editor but this is disabled in the Editing Experience settings. So you can go to Toolset -> Settings and scroll to Editing Experience and select the 3rd option. This will give you access to both the Block and classic editor.
For the foreseeable future the views classic editor won't disappear and the Views plugin itself will still continue to receive updates because as mentioned blocks and views are the same plugins.
Features will continue to be added to the Block editor which makes it easier to use but if you're not ready to make that jump yet the Classic views editor will still be available.