Hi all,
I have this issue too, but I found a solution which partially works for me:
I added a shortcut so that as soon as my image is imported I can click a shortcut which aligns it in line but works best when pasting at the end of the document, otherwise it just throws the picture wherever (in this case I suggest cutting the image from its current location Cmd+X and pasting it in your desired location).
So here's how to add the shortcut:
System Preferences > Keyboard > Shortcuts (tab) > App Shortcuts (tab in left pane) > + (sign below right pane)
Select 'pages' instead of 'all applications'
Write 'Inline with Text' in the empty box
Click in the Keyboard shortcut box, then add your desired shortcut (mine is Cmd+i)
Click Add
You are now able to make an image go inline with text automatically - this will work only if you have already selected Format > Arrange
So if you have another option selected while trying to move image inline with (in my case) Cmd+i it won't work.
I guess you can also add more shortcuts to go first to Format and then to Arrange faster but in any case this is a hassle.
If this is annoying you as much as it's annoying everyone else, please fill in a feedback form for pages found here:
Feedback - Pages - Applefor Mac users
If more people complain about this, there is a better chance of getting this issue resolved.
Best wishes to all