Q: suggestions for optimizing...

The iCab browser still uses Flash player, however the Adobe player

available by download from their archive site is not considered able

to work with many current demands for Flash, nor is there an update.

•Adobe Flash Player - Flash Player Help:

http://helpx.adobe.com/flash-player.html

A patch to put a newer part into an already-installed Flash player,

is out there from a few years ago, and in some cases it may help.

The download includes an instruction page.

•Adobe Flash 11.5 for PowerPC (see 'read-me' how-to use it)

http://scriptogr.am/nordkril/post/adobe-flash-11.5-for-powerpc

You also can try the HTML5 Player information from Google/YouTube

to see if a chosen browser could utilize any HTML5 video available...

•YouTube HTML5: http://www.youtube.com/html5

Also if you choose to use TenFourFox, the current versions do not

allow Flash to run, unless you use the 'about:config' access in the

browser to open the hidden preferences, and set it to accept Flash.

You would have to buy an older retail iLife DVD install disc

to get an iLife 09 or before. Check the specs to match the

OS X version 10.5.8, and the hardware your Mac has.

There are options for replacement had disk drives, but not sure if

that old of PPC portable with ATA/IDE (PATA) hard drive bus, can

use a faster spin-rate (over 5400RPM) however the ATA drives

are getting harder to find. I do see a few options at OWC macsales

online, to include a Legacy SSD drive that can work in G4 iBooks.

That solid-state drive could make an older iBook G4 14 or 12 fly.

If the original drive is still inside there, it is rather old and worn;

as such, may run hot or be subject to failure. It also may be too

small in the capacity, so features necessary to have OS X run OK

in an older PPC Mac may be compromised or slower. The need

for free space to be used as temp swap files, or virtual RAM, etc

is important. So that may also be a reason for it to run slow.

Online streaming may also be slow, where or if available, and part

of that slowness could be if the computer is using a slower wi-fi

connection, or a faster Ethernet cable. The latest wi-fi specs are

not supported in the older AirPort specification at the latest speed.

So, anyway there are a few things you could try. If you attempt

an upgrade to SSD, that can be a headache; there are a few

known issues, but be sure to get an older legacy series SSD

such as macsales.com has for vintage 2.5" drive computers.

They also have installation video and other information. Then

the iFixit.com repair guide for that series iBook is helpful.

Good luck & happy computing!

PS: while attempting to post a reply the ASC site failed

and in order to access my account, I re-logged in.

{edited 2x}