Can multiple applications cause power/booting problems?

[New Daddy]

Symptom

My phone has the following symptoms:

(1) The phone will not wake up (will not turn on even when I press the power button).
(2) Sometimes the screen whites out (gradually turns into an all-white screen) while in use.
(3) A soft-reset will not reset the phone. Sometimes a soft-reset will result in a white screen (the kind that I described in (2) above); sometimes it will lead to the green, "booting" screen of Windows Mobile but doesn't progress from there; sometimes it will lead as far as to the today screen but then the phone freezes; other times a soft-reset does the job and put things back to normal. But then (1) or (2) happens again, requiring me to soft-reset the phone... You get the picture.

These symptoms come and go, but recently it was becoming more frequent and persistent. Yesterday, the straw broke the camel's back. My phone was out of operation most of the day.


Current Status

As soft-reset would no longer bring the phone back to life yesterday, I had to hard-reset the system and installed only the most basic apps for now (PIM manager, dialer skin and an IME). It's been one day after the hard reset and I haven't had the previous problems so far.


My system

XV6700, Windows Mobile 5.1.461 (Build 15671.3.3.0).
I usually have quite a few apps installed on my cell (agendafusion, wisbar, spb backup, spb mobile shell, spb pocket plus, sk tools, IME for a foreign language, dialer skin, etc.), some of them in the main memory and others in the storage card. I also did a number of registry hacks to finetune my phone. No ROM flash though.


Questions

Prior to the latest hard-reset, I was suspecting the symptoms arose from a hardware problem - either the phone itself or the battery. I took the "white out" problem as a hint of a battery problem. But now that the phone is working fine (so far) after hard reset, I'm not sure any more.

Can the multitude of applications and registry edits affect your phone in a way to cause the symptoms I described above?
I can't use my phone as it is now without installing all the power apps I need on a day-to-day basis.
What should I do find out if, indeed, the overload of softwares was causing those serious problems?
If so, what can fix it?


Thanks.