Start-up issues relating to power & battery

MacBook Pro 15" Core 2 Duo Model A1286 (late 2008)

Problem: Difficult to start-up with-out battery. Machine behavior inconsistent.

Context: The battery does need replacing (it's bloating). Also a few years back (3 or so) my bag slipped from my shoulder and did drop to the (hard) floor creating a dent on the front-right corner over the years it had no apparent effect on using the system. But, I did notice that a screw (back rear-left, kitty-corner to the banged corner) could not be taken out (the threading was somehow shot). Thus, some shock impact was felt at rear-left where the MagSafe connection is located.

Recent history: Battery cover started popping out. Closer examination revealed that the battery was bloating. I was away and worked with the unit, without battery for a week. I got home plugged it with a second power adapter I have and it failed to start; only with the battery in was I able to operate the MBP.

I subsequently found information here (MacBookPro does not power up on AC power or battery which allowed me to identify the problem with the 2nd adapter (it was a 60W instead of an 85 W). But, in the meantime I did follow Victor Clausson's advice and managed to start on the 2nd power adapter without the battery. Negative bonus: the famous jet fan noise.

Could not use the main adapter (which is the original unit, I believe, but has not indication as to wattage) without the jet engine running. SMC re-set the fan to normal.

a) is there a way to know the wattage of the adapter.

The OS (10.6.8) may be going flaky. The unit will not re-start without battery. Once booted up it will state no batteries available, or will show 0% (it may be discharged having been unused in 6 days). System preference Energy Saver has analogous flaky behavior. boolean 'show battery status in menu bar' would be false. Setting it to true would toggle back to false. After 3-4 tries it stays at true.

b) Could an OS plist file gone awry? Does the battery's condition lead to this behavior?

c) Although I understand running without the battery reduces performance, NONETHELESS how can I do so effectively?