Setting optional objects:
If you are on a page in x5, so in step4, you have top right a pulldown to filter several objects you can use (blue arrow).
Next to it there is a manage button (red arrow), press it, the next screen needs to be updated, use button on top (green arrow).
There you have several extra objects to install (select and press install) remember the chapter where you found it then you can easily find it back in the normal page in x5 by using the top right filter. After installing finishes press ok.
Not all are free some can be bought using Credits.
You can find the object now under the filter from the object chapter or use all in the top right filter, remeber the blue arrow.
To check your credits or buy them go to the helpdesk of x5, press top right next to your name pulldown, then select credits (yellow arrow).