On figuring out a summer throw

I need some advice here.

The idea of a summer throw started brewing in my head shortly after the one of a Certain  Uncompleted Great Romany Blanket.

But it stayed there.

Slowly I began gathering a few possible patterns on Pinterest, look at possible colours in Vinnis or Bambi and then drank a coffee and forgot about it for that day.

Then winter-that-was-just-a-rumour ended, I took the winter duvet off already by the end of July, and during the three days that spring lasted I realised that I am not going to make it through summer under a summer duvet.  It's just going to be to hot.

Rewind to Summer Throw Idea and fast forward to actually start doing it.  

A day was spent roaming the net for possible square patterns.  It had to be light, lacy, open, as to not be too warm.  It had to be neutral enough so my poor husband would have to sleep under a girly throw.  Multi-coloured was going to take to long, I didn't want to work masses of ends away.

In the end, I decided on the Coral Trellis Square from the book 75 Crocheted Floral Blocks:

One done, now for joining

It came out nicely; I blocked it to make sure, so then it was onward to see how I would join, and that is where I hooked myself into a corner:

See?

I want it open and lacy, yet not with these huge holes - fingers and toes and kids' elbows get stuck in it and it's a tear waiting to happen. 

This is how it would look following the join  recommended in the book:

Nope

A friend suggested I join it like a puzzle, e.g. a SC join into the three long picots, and extra picot joins into the SC's:

Also not quite right.  

Need to figure out what to do before I fall out of love here.  

Do I make plan C?  Or do I use another motif (Plan D, E or F?)

Or do I just use a plain and simple Granny Square, maybe doing the clusters as DC3tog, join-as-you-go, with an interesting edge?  Because the Nikkim Bambi yarn is nice enough as it is.

What to do?
What Would You Do?

PS...I'm also wondering - should I take the hook down a notch or so?  Did the above with nr 5, because I like loose work, but maybe I should try out nr 4.5.