Well, I am wondering wether you actually need a high Perception for the SMG anyways. When it is done as a melee/SMG combo I guess you should be able to get pretty damn close to the enemies, and thus making it easier to hit.
I have been looking through some of the feats in regards to your stat allocation, and as I can see there is:
Uncanny Dodge, requires 8 Agility. (VERY, VERY useful against sledgehammer opponents.) which you did take.
Hit and Run, requires 7 Agility, which SEEMS very useful for a fast-attack melee build.
Aimed Shot requires 6 Perception (which you dont have), but seems quite unnecesary for this build anyways.
Suppresive Fire also requires 6 Perception, this could be useful, but not vital. So I guess not so important.
Kneepcap Shot requires 7 Perception. It gives a bleeding wound on the target, but then again, it is just 1! bleeding wound, compared to the Burst fire giving potentially A LOT more. Not worth 3 stat points.
Cheap Shots, 6 Dex and 5 Int, giving Melee +50% crit damage, and 15% chance to incapacitate, very useful for this.
Expose Weakness, 5 Int, VERY usefull actually for a tough enemy. Build a ton of bleed stacks, then use Expose Weakness to lower their mechanical resistance, and then WHAM it with the Eviscerate!
Spec Ops, requires 6 agility, and cuts 1/3 of AP cost from SMG burst, so vital.
Soe... as far as I can see, you dont loose much but only having 4 Perception. The only thing I am curious about, which will only really show up as you start playing the build, is if the 4 Perception gives enough %to hit with the SMG. If it does, it makes sense only keeping it at 4. Since we mostly use the SMG to apply Bleeding Stacks, the actual damage done by the SMG is not so important. So as long as we can hit stuff, we are good.
I agree with keeping the Con on at least 5, so you dont end up with a glass cannon.
On the Robots, what I usually do with the early, bullet-shooting robots, is to craft a good Tactical Vest, with a nice Damage Threshold against bullets, making me immune to their attack. Then I can take my sweet time in slowly chipping away their HP. Sometimes horribly slowly, but it gets the job done. Also I like Expose Weakness against robots, makes it possible to suddenly hurt them with melee.