Are you answering on behalf of Sparx?
Because all those issues has been already confirmed by Sparx support as issues to be fixed in future release(s).
Any way:
Is there any reason why an option not existing is a bug?
Because:
1. I had existed in v13.5, but removed with no reason in v14
2. Similar option still existing for elements. Again, missing this option for connector is unjustified
3. if I can color different type of connectors using the same filter (ie tagged value), I need to create multiple redundant Legends.
4. besides this option does not exists on the list, it's still possible to achieve this feature, by not touching connector type drop-list: so drop-list shows "Aggregation" while a Legend behaves like "all types".
Isn't it enough?
Sounds like a bug, but not one that's going to prevent you from modeling.
You missed the fact, that a Legend is not a modeling tool but diagramming one.
Despite someone here confirming the behavior is what you described, I have a feeling that it has something to do with the 'Use alias field for role' option on the behavior preferences page. The '/' denotes the role. "Fixing" it for you may be the exact opposite for other users.
No. Whatever I select, it doesn't show values properly.
Here are settings you are talking about. It's pretty clear that it should give possibility to display Alias only without name.

At first, those options are valid only on diagrams for which 'Use alias if available' is enabled. So, why alias is rendered next to name if this option is disabled?
At second, if 'Use alias if available' is enabled, there is no option to suppress displaying a name. Doesn't matter what combination of option I use.
I don't know what 'Alias only' means for you, but for me it means alias only, without name.
Also EA manual says: "Select the checkbox to use the Alias property of
instances of elements to show the Role property". Mentioned issue appears on
classifiers too.
So... it seems like 3 bugs in one feature. Achievement acquired

And to back to the topic:
TBH I cannot see any bug listed in changelog.
That doesn't mean that no bugfixes where included.
Really?
From announcement post:
For a full list of features and fixes included please see:
and from history page:
Changes and fixes for Build 1500 BETA