Yep, presently in T:ANE CE 1.1 you can not merge anything as there is NO merge function implemented yet. Otherwise it would be a cinch to start creating a new route, but as said, no merge function yet, so no new larger route can be created. One baseboard is all one get to do this but it is enough to create and save some consists to run on other routes one might get into T:ANE when using the "drive only" option of the build in routes.
I should also say, instead of UNINSTALLING T:ANE 1 as the install directions for T:ANE 1.1 said, I simply added three xxx in front of the c: Drive user/userdata folder, renamed the TANE.exe of T:ANE 1 to xxxTANE.exe, relinked its user/userdata folder to that with the install path of T:ANE 1 and now have 2 operating T:ANE installs on my PC, V1 and V1.1 on 2 different partitions. I did this for comparisons only.
Also, one can not export a CDP out of T:ANE 1 to load into T:ANE 1.1, if I do so, the ending on the CDP has 2 extra characters shown, like xxx.cdp*# or something like it. When dropping this as is into CM, even deleting these 2 extra characters to make the file name xxx.cdp, it comes up as "unknown" and can not be installed.
However, there is a workaround, one simply opens that troublesome route for "EDITING in EXPLORER" in T:ANE 1, copying that open folder onto the Desktop or wherever and dropping that so opened folder into T:ANE 1.1, where this will now install. Opening a "missing dependency" window in CM will show you all missing dependencies, which one can d/load from the DLS, faulty or not.
More often than not, such imported route will open up in T:ANE 1.1, I did so with my 400 plus baseboard monster route which I created first in TRS04, installed it later in TRS06 and finally into TS12 31688. I think this is the secret of importing older routes, loading this into TS12 first, then making a CDP (in TS12) of the ROUTE ONLY (check the item icon on the left in TS12 CM) as if exporting a session only you will get an "unknown kuid" error of your imported route in T:ANE 1.1.
Then as said above, check its missing dependencies, highlight them all and d/load these from the DLS. After that, if your imported route shows up in Surveyor, you WILL still get some missing or faulty dependencies, get missing textures, missing stations and tracks, broken tracks, bridges and tunnels etc. as the above pictures of the OP show but once as said, the "replace this with that asset" in CM is working, you can rebuild your older imported route to its former glory with quite a few newer and better ground textures, buildings, splines and trees etc., once these become available in the next few weeks/months/years.
I think I read somewhere else, only bridges and tunnels for TS12 V3.7 (or is it 3.8) should be used for T:ANE as most tunnels and some bridges in my imported monster route were missing. Again, these should be easily replaced with new ones, once the "replace asset with this asset" is implemented.
I also get a lot of older trees shown in my installed monster route, most of these are not too bad looking in T:ANE 1.1.
I hope this helps some of you.
Cheers
VinnyBarb