Alkalines, especially cheap alkalines, can be unreliable. Very unreliable. Seriously, try NiMH.
Also, one trick I use is to mentally 'time' my flash recharge. I can hear and sense how long the flash takes to charge. I use a 430EX and NiMH batteries, a full dump at max power will take me about 3-4 seconds to charge.
I shoot a lot of events and VIRTUALLY NEVER fire at full power except in very special circumstances (daylight fill trying to overpower the sun at small apertures). If I hear the flash pop that loud and take 3-4 sec to cycle, I know I am most likely doing something wrong. This same flash has survived more than a hundred events since 2005 so perhaps the 'power management' helps
Strangely, I have never felt the need for an external pack. The 430EX doesn't support one. And the batteries never get that hot. My usual event zoom lenses are not particularly fast either, f/4 or f/5.6.
Hope your flash gives you a second chance and lives a long life too
PS: alkalines becoming dangerously hot to hold might indicate an internal short, near-short-circuit condition, or WAY too much power being drawn from them, more than they can handle... either way none of the above is a good thing!