Are integrated amps technically better than separates?

Tim, you may wish to consider upgrading the 3.7i jumpers, and the power cord(s) and XLR. I would guess Magenpan might frown on the jumper replacement, and of course it would be "do at your own risk", however there is discussion of it to be found. 

These would improve the performance significantly. :)

Regarding the jumpers for the speakers, refer to my review of the Maggie .7 at Dagogo.com

As might be expected, answers will vary.

Without comparison of actual units this is a thought exercise only having limited benefit to actual system building.

Results vary widely and wildly dependent upon the particular components and system build.  :)

Ditching the preamp may, but certainly is not, an assurance of superior sound. Soundstage and tonality may suffer without a preamp. But, of course, apart from actual comparison the responses are generalities that can be overturned in any comparison.