New fitting issues

Hello! I'd like your opinion on a muslin I've been working on. I want to sew this dress from Burda:

I made a first muslin and there was the swayback problem as well as some strange horizontal fabric bunching on the front bodice so I made alterations and here's my second muslin:




I think this is obviously too tight with the fabric pulling at the sides and the fact that blood stops flowing in my legs when I sit in it :( Yes the peachy bits you can see in the top pics figure straps because I intend to put some on the final dress. What do you think, should I let the side seams to gain 1 cm on each side? Or should I add 1 cm in the middle front and back? Or maybe both?! Once again I need your help girlz!

Butterick B4985 second muslin

Hey there! Following yesterday's pattern alterations I made another test top and I'm quite happy with the result:


Those sharp angles I was worried about worked well eventually! I lengthened the back pieces at the hem and drew a curved line to make it harmonious. I know it's not perfect but I'll leave it like that since 1) I'm not a fusspot 2) my weight varies by 2 pounds almost every fortnight. I also slightly altered the sleeves by superimposing the big dots on the back and front sleeve pieces to join them:



To me the sleeve has a nicer drapé like this, even though you can hardly see it in the picture of the muslin -I totally forgot to take side views^^!
Well I guess that will do for the fitting part, I'd like to get started on the real thing but I'm afraid to cut into one of my hoarded/treasured Japanese fabrics so I'm probably going to think about this one a little longer... See you and thanks for your advice on yesterday's problem!

Fitting issues

Hello dear readers, how are you? I haven't posted much recently but I've had seamstress block, I can't seem to sew a proper thing for me :( Strangely enough I had no problem making garments for relatives but for me it just didn't work! That is, until I dug Butterick B4985 out of my stash:


What a cutie! A quick look at some sewing blogs later and I was definitely convinced, I had to sew this one. As I'm rather wary of non vintage US patterns when it comes to the fit I made a muslin. The result is quite satisfying except for my usual sway back problem. Here's what I did to try and solve this issue:


I pinched 1.3/4" of excess fabric in the middle lower back piece and removed 3/4" along the upper piece seam line. Now that's when I need your help: are these alterations enough? Should I alter something else? I wear a lot of loose tops so it's difficult for me to say if this above is correctly fitted :( Also please look at my modified pattern pieces:

That piece n°6 now has a sharp angle at the back seam, is it ok or should I reduce the sharpness by sharing the extra centimeters like this:


And of course I guess I have to make up for the 1.3/4" I removed by adding the same amount at the hem of my modified pieces like this:


I could really use your help so please share your advice in the comments! Thanks!