Before asking questions, try and make yourself more familiar with the viewer: browse the preferences (will work for "select where to save things"), and do read the tool tips for every check box, browse the main menu (including the Advanced menu), browse the Inventory floater menu and context menu, etc.
This forum also got "howtos" and various articles to explain how the viewer works and where to find things.
E.g. or user_settings location under Windows, this can be found in the
Windows installation HOWTO. Under Linux things are even simpler (everything can be found in your Linux account
~/.secondlife/ folder).
Then, use the "Search" feature of this forum to find the corresponding answers. Example:
Finally, do not expect to see every other viewer's features being present in my own viewer. Instead of implementing a gazillion features, I implemented Lua scripting. I prefer to add Lua functions when needed to be able to mimic specific features via Lua, than bloating the C++ code with such hard-coded features that will be only used by a few users, when at all, and will likely not even suit every of these users' needs or preferences.
My viewer is coded for stability and speed, and both of these are incompatible with code bloat.
It is also a viewer geared towards advanced users.