Magic is a complicated art. Here are a few notes regarding the interplay between intents, bases, durations, etc.
This page is likely to grow a little as further notes are added.

Notes on Duration

An important consideration regarding duration is that it has different meanings for different intents. Remember that the duration is the length of time that the magic "works". That means whatever effect is created will last for this duration, and afterwards non-magical reality asserts itself again.
That means that for some magical effects, once the magic ends, things revert to normal - levitating something means it comes crushing down when the magic ends. For other effects, for the same reason, nothing happens when magic ends - moving something to a different place horizontally means when the magic ends, it will stay there, and not move back, because there is no force pulling it back.
For some Intents, like Create, Change, Heal this is very important. An unnatural creation will vanish once the magic ends. So a magical flame created via Create/Fire will go out once the magic flow stops. Any fires it started, however, will remain burning. Only the purely magical flame itself will go away, since fire uses up energy and if it has no fuel, it goes out - that's physical reality. A rock created out of nothing via Create/Earth, will remain in existence after the spell ended. Because in non-magical reality, solid things don't simply disappear.

For Change, Heal, Move, etc. spells, the duration of the spell is usually the speed of change. As a basic rule-of-thumb, any such spell should have a Duration at least as large as its Effect. Otherwise, it will put stress on the material it changes, and (especially for healing spells), cause a lot of pain in the target if is a living being. One level of difference can be considered uncomfortable (for move, etc.) or painful (for heal, etc.) while two or more levels will cause considerable damage.¹
This being a general rule, there are exceptions. A healing spell to stop bleeding for an hour, for example, would not take one hour to take effect, it would stop the bleeding very quickly and then last for one hour. Again, this is very obvious and easy to see: The magic effect is that bleeding is stopped, so after the duration ends, the magical effect ends and the bleeding continues.
Yes, if you are creative, this means there are "real" and "temporary fix" healing spells. A spell to "really" heal a wound would slowly close the wound, grow tissue back together, etc. - taking time but doing it in such a way that when the magic ends, the wound is actually gone. It is possible to magically force the muscle and bone together very quickly and hold them there by pure magic force, "healing" the wound almost immediately - but making ot break open again as soon as the magic duration has ended.

All this sounds complicated, but really is very simple: What happens when the magic ends is that physical reality returns. With that in mind, it is very easy to see what happens when the duration of a spell ends.

Notes on Transport and Teleportation

As already outlined above, Move spells should have a Duration comparable to their effect. But what distance do they cover? Basically, use the Effect value like a second Target value. A Move spell with an Effect of 1 could flick a switch or move things around on a table. Flying around would need at least Effect 3, or even 4 if you want to gain height. Teleporting to the other side of the room would use an Effect of 3 or so, teleporting to the other side of the country would only be possible with a ritual and an Effect of 6.

One effect of the "short duration = stress" rule is that teleportation spells are very hard to create. One way is to create a "substitute" with the required duration, e.g. a portal that requires an hour to charge up before (instantly) transporting the caster around. That's fine - the laws of magic are not the laws of physics, and that the body moves instantly is not what would shatter it. The problem of "delayed" spells like this is that the destination has to be choosen at the time the spell is cast. Another option is to cast a protective spell to prevent the disruption, something like Protect/Body would work for the caster himself, with an effect at least as large as that of the teleportation spell. Again, one level less is acceptable if you are willing to accept some discomfort or pain.
So for an "get out of here right now" teleportation spell, you could cast Protect/Body 3-2-2 (duration 1 wouldn't cut it, you risk it ending before the teleport is complete) and then Move/Body 3-2-1. Alternatively, Protect/Body 2-2-2 would be enough to make the teleport safe, but uncomfortable/painful.

Notes on Magical Perception, etc.

You remember from the Energy chapter that energy can not be affected by magic in any way. This is the reason for there not being a Base called "Magic" or such like. This also means there is no such thing as perception of pure magic. Identifying someone else as a magician, or determining his energy level, or even just "feeling" magic being cast nearby would require a Perceive/Magic effect, and since the base "Magic" does not exist, there is no way to detect magic with magic.

Notes on Summonings

Using Create, supernatural creatures can be brought into this world. The question of whether they are created from nothing or summoned from another plane is largely theoretical, the fact is that they can be brought into existence.
However, Create does not contain Control, which is a seperate intent. For natural objects created through magic, that simply means they follow the laws of physics - a stone created will fall if not created sitting on top of something, a flame created by magic needs to be handled with the same care as a natural flame, etc.
So summonings as we know them actually need two spells - one to summon/create the creature and one to control it. Obviously, interesting things are bound to happen if the duration of the control spell is shorter than that of the summoning spell. The Target should be identical - who wants to summon a skeleton army and only control one of them? And Effect will usually be identical, though one level below the summoning will give limited control, enough to put the magician out of harms way or giving the summoned creature a very general command. For example, if you want to summon some kind of fire demon and turn it lose to kill anyone in sight except yourself, one level below would probably be sufficient. Just don't use it if any friends are around. Likewise, if you want to make really sure, one level more than the creature's effect (aka power) would be wise, just to make sure it doesn't do "creative interpretations" of the commands given.

¹ Sidenote: This is not a cheap way to create torture spells. Such spells have an Intent of Harm - the pain in this case being a side-effect, it is not guaranteed and is likely to not occur if the real intent is to cause pain. Remember that magic is in the mind.