Before you do anything establish what they are!
Frankly they are better gone. They were out of scale and just wrong. Rest easy, you have done the right thing.
Never pick beyond the longest day. I don't know if this applies to young asparagus plants like yours, but it does to older ones.
You don't bear them any ill will - so you killed them!!
Make sure to spread lots of seeds where you do want them later in the year.
Don't take off 2 foot, they will just be ugly. Get rid of them if you can. But it does depend on their height.
And what about foxgloves? There are many, many poisonous plants, but vanishingly few cases of poisoning.
Don't cut it and take it indoors. It smells of cat w**.
Looks like cotoneaster to me.
Magnolias don't like to be pruned. They are apt to produce a lot of unproductive shoots.