Still is because of the depth in-game which Oblivion doesn't have, but the graphics is much better in Oblivion than Morrowind in vanilla anyway.
Morrowind Code Patch or we in the MW-community often say MCP has only one purpose and that's to fix glitches in the game like the Alchemy name bug plus a lot of other bugs, but AFAIK MCP has nothing to do with more realistic exterior in-game unless MCP has an exterior bug to fix.
That's a correct installation order, but you don't need to install any patches if you have the GotY version.
Installation of Morrowind with all expansions (Tribunal, Bloodmoon) have exactly the same process like Oblivion, because once the installation is finished the game has been patched to the latest.
That's normal and it simple means that you need to update the masterlist for the esm/esp, which you can do in two ways first load the plugin (only esp) into CS then save it or you can update the masterlist (the same thing will work in both Wrye Mash and Wrye Bash not sure about Wrye Bash for Skyrim) in Wrye Mash on the Mods tab.
Every error you get is often stored in the Warnings.txt file in the \Bethesda Softworks\Morrowind game folder. These two errors below are normal and can be ignored.
Texture "Textures\_land_default.tga" count 3.
Texture "Textures\menu_thick_border_bottom_right_corner.dds" count 2.
Personally I don't consider the Real Sign Posts mod as an essential mod, but many people have some of these listed mods in their loadorder and that reminds me to mention mlox which is an definitely essential tool for a modded game.
See above about patching of the Bloodmoon installation.
Yes you can determine what version you have by launching your game and look to your left bottom in the game menu or pressing the ESC key in-game, but MCP installed will show the MCP version.
Retail version Morrowind - 1.2.0722 Tribunal - 1.4.1313 (you can install this patch over the 1.3.x version) Bloodmoon - 1.6.1820
Steam version Morrowind - 1.2.0722 Tribunal - 1.3/1.4 (not sure if you can install the 1.4 patch over the 1.3 patch) Bloodmoon - 1.6.1820 TES CS Patch (only work with Steam version of Morrowind)
Here some tweaks you can do by your self. Open the Morrowind.ini in Notepad and add/change these lines.