Problems with custom install of MATE

[Richard Owlett <rowlett@cloud85.net>]

As I have a very low data cap and wish to avoid some "recommended" 
components I have done:
1. a text mode install [including "standard utilities"] using
   debian-11.2.0-amd64-netinst.iso .
2. apt-get --no-install-recommends install mate-desktop-environment
3. apt-get install xinit
4. apt-get --no-install-recommends install xorg gparted synaptic pluma

Between those steps were searches/fixes for some things that didn't run 
as expected.

Current questions/problems include:
1. Why do I have to manually run startx at each boot?
2. Although menu entries for gparted and pluma appear as expected, there
   appears to be no way to launch synaptic.
3. Although connected to internet [i.e. apt-get runs correctly], the
   appropriate icon does not appear on MATE's taskbar.
4. I'll be installing SeaMonkey but have forgotten how to have it appear
   on appropriate Applications sub-menu.

I've done it all before but can't find my references.
Help please.
TIA