Steel Frame Moment Connections Layout and Detailing

[lexeng18]

Hi all,

I'm working on a project that is 2 stories, structural steel superstructure with moment frames in each direction for the LRFS. Seismic design category B so R=3. Despite the relatively low seismic parameters, its quite heavy and seismic is controlling the design with some pretty substantial forces (~650 kip-ft worst case, service level). Heres some concerns I have that I'm hoping to get input on:

1. I was entertaining using bolted end plate moment connections because in my experience these are less prone to field issues and fairly easy to erect, but these connections requite a thick end plate with stiffeners and (16) bolts such that the entire connection will protrude above the 6" slab-on-deck.
   1. Is this alone reason enough to pivot to bolted flange plates instead, maybe providing ~1/8"filler gap for the bottom plate to facilitate erection?
   2. I try to use slip critical bolts and oversized holes for flange plates typically but not with loads this high. Should I still plan for that approach or switch to standard holes?
   3. Any reason to favor welded flange plates or other connection types that I'm not considering?
2. The customer is expecting the elevated slab to perform very well with respect to crack control. For areas where I have these moment connections, is there any special detailing I should consider to permit the connection to rotate as it needs to without negatively affecting the slab? For example, at vertical bracing connections I have seen some firms specify compressible material at the gusset for inelastic rotation to take place but I haven't ever seen anything for moment connections. I also need whatever I specify, if anything, to be unseen from above as most of the floor will be polished or epoxy coated concrete with no other floor coverings.
3. More generally, my approach right now is that I'm dedicating ~3-4 single bay wide frames in each direction to be the moment frames, and obviously at these locations the column sizes are quite big and that's why there's so much load at each connection. Another approach I have seen but never done myself is to go with moment connections for all beam to column connections across the board. I've always been taught that moment connections are expensive and a pain to fab/erect so to reduce their quantity, even at the expense of heavy steel. But this approach does have the benefit of permitting far more uniform column cross sections and reduces the load to each connection to something likely very reasonable. Anyone have any experience on this front?

I would appreciate any and all responses, even if its only to a piece of what I'm asking or tangentially related!