PPRuNe must have picked up about 20 newbies this week from the flying school brigade. There has to have been a marketing campaign!
You can enter a D zone from any direction although if transiting a place like YBMC or YBSU as its about to be known and travelling coastal for example it makes life easier than if you wanted to use some unusual course.
If you have a plan in the system even VFR, you will be processed easier I would imagine, and report inbound at whatever height on whatever radial (thats opposite your track
) received the ATIS and request a clearance for whatever. Should work just fine.
Is this a bait for a GAAP v new D???? Sounds like it!
J