Concentration

I’m pretty suse I’m  never gonna run out of spell slots what with all the good spells being concentration.... sigh.

Great if you need to kite, but otherwise I think it's just outplayed by stuff like Mage Armor and 1 level multiclasses into fighter to get advantage on armor. It's cool for Rogues!

Rouges get "Cunning Action" at level two, which gives them the benefits of this spell for free. 

Can I use my primary action as dash and then use this as a bonus to dash again after?

yes

Monk 18/Wizard 1

Casting word is:

Evacitus Abruptus

Or just Rogue 2 instead of Wizard 1, then you don't have to worry about spell slots or concentration.

Pretty great spell for transmutation wizards though. Bonus action cast and allows you to change the effect of your transmuter stone

Adding the "Mobile" feat with "Expeditious Retreat" makes for an interesting selection for Bladesinger Wizards...with Bladesong, that 10ft of movement has the Bladesinger moving ar 80ft on a bonus action...darting in to stab with impunity.

"Mobile" is good with "Expeditious Retreat" & "Shocking Grasp" as well...zap enemies without fear of opportunity attacks, and potentially nullify their reactions for the turn.

you might be able to use it along with dimension door to save allies, or reposition them to make them more efective, and you can be more efective if are a wizard from the school of transmutation to increase your move speed as you cast it. Just thought about it, it looks kinda cool.

I found this very useful on our Campaign for my Gnome characters. The campaign has a fair amount of encounters were we need to dash to or dash away. With a movement of only 25' as opposed to 30', the Gnome normally lags 10' per round during dash round. Casting this spell, the character can double dash. 

HIGH TAIL IT OUT OF THERE SMOKEY!!!

But how do you cast expeditious advance? O.o

Despite the name of the spell being retreat, there is nothing in the description to say that you have to be retreating.  So i'm assuming that you could use this to advance as well?

Quote from Chayne_Nox >>

Despite the name of the spell being retreat, there is nothing in the description to say that you have to be retreating.  So i'm assuming that you could use this to advance as well?

Yes. The name of a spell doesn't define what the spell can do, only the description does. This spell allows you to use a bonus action to take the Dash action on your turn, which increases your movement speed. It doesn't say that it places any restrictions on what you can do with that movement, so you can use it in any way you normally could.

Contingency spell, when turned into a windwalked cloud, you get to go flying with a double dash right?

Where did the extra level go.