Lorby_SI

The sequence in which you initially install these addons on your PC is of no consequence. TD asking for a weather engine is just a convenience function, it doesn't really need that information to work (and you can insert it afterwards too, in the TD settings). TD is perfectly fine with only the built-in weather in your simulator too.
 
The texture addons have a GUI interface, you can change to multiple different texture sets any time. All that these programs (Rex4 textures and Rex SoftClouds) do is to copy a couple of texture ("picture") files into your sim directory. After that process is complete, you close the addon. From that point on you will always have that specific texture set in your sim, without ever starting the texture addon again. You only fire up Texture Direct or SoftClouds when you want to change the texture themes to something else (they have a ton of different "styles" for environment depiction). And here is where some sequence is needed - Rex4 TextureDirect includes low level clouds too, and it overwrites SoftClouds textures. So if you are using SoftClouds, you have to open that program after you have finished with TextureDirect and inject the SoftClouds again. (Edit: that depends on your version of TD actually - you can integrate the SoftClouds product into TD somehow)
 
The weather engine on the other hand (no matter if it is Rex+ or ASN) has to be active alongside your simulator all the time.
 
In a broad strokes, both types of products interact like this: the texture addons (re-) place pictures of clouds, sky, runways, water etc. in your sim and the weather engine tells the sim how and where to display them.
 
Weather Architect is a completely independent product too, you can use it any time you want. Just just have to make sure that any weather engine that might be running doesn't interfere (=if ASN interferes, just close it - it is an external program).

?
Just add the null-characters where you want the menu items to be split.
 
C#
simconnect.Text(Microsoft.FlightSimulator.SimConnect.SIMCONNECT_TEXT_TYPE.MENU, 0, Event_id.EVENT_MENU_1, "Title Menu\0Choose item:\0Item1\0Item2\0Item2")
 
VB (assumed code, havent done this in a long time)
simconnect.Text(Microsoft.FlightSimulator.SimConnect.SIMCONNECT_TEXT_TYPE.MENU, 0, Event_id.EVENT_MENU_1, "Title Menu" & CHR(0) & "Choose item:" & CHR(0) & "Item1" & CHR(0) & "Item2" & CHR(0) & "Item2")

 
Be careful with assuming the functions "are the same". This is not true for all of them, some work quite differently. And if you plan to go that way, be advised that P3D (V3) SimConnect is a little different as well, even if the doc looks the same at first glance - there are some subtle differences, almost hidden in the documentation, that have huge consequences. For example, in P3D V3 you have to explicitly cancel a data request on an object, even if that object has been deleted (!). This was not necessary with previous SimConnects, FSX knew that it makes no sense to send data for an object that does not exist any more...

I'm using Simstarter for this, works very well and has a ton of useful functions on top.