Ive put it off for too long.... its about time I ask for help on this

Im having a strange problem with my brakes, sometimes they act normal.
*mostly when its warm*
1.it's get very hard to depress the brakes sometimes

2. Some times my car acts a lil sluggish and I pry the brake pedal and it goes I presume it stick's
[Dunno if thats the proper terminology]

Ive done some poking around when adjusting my suspension and noticed some gunk around the calipers and I presume that there leaking which could cause some of the problems but also makes me think my Booster/master is going bad.

My second issue is that I noticed when it's Humid or Insanely hot like florida has been as of late
My car act's like a 5 year old and doesnt want to start. It will just *Click*
Fuel pump kick's on and there's fuel and Spark. Just click's
I've replaced the following and still no luck

-Ignition Switch (The piece by the key cylinder)
-New battery
-Checked grounds and the chassis resistance (1.8 Ohm's)
-Had the starter check at advance test better then normal

Ive replaced the Switch three times the
The first time thinking it was that causing the issue.
The second time was when the said "New" switch decide too melt the solder off


** Car's a 91 S13 with a KA with a lame ass Autotragic