As noted, the "final security checks" mentioned in your documentation are no longer there, so you can move freely between the PAGstop and the CX lounges (they are less than 100m apart). I wouldn't get there especially early to spend time in the CX lounges - they are fairly basic; they can make a decent espresso on request though.

If you want wireless access in the CX lounge you need to ask for a password from the attendant (I assume this is available free of charge to J lounge people as well as F, although I'm not sure).

Depending on what time you are flying and what your CX status is you may also have access to the BA/QF lounge (adjacent to the CX one and much the same) and the JAL one (which I haven't tried yet).

The departure tax is indeed now PHP750 payable in cash - I believe they also accept US$ (probably about 16 of them at the moment).

I tend to make sure I am at the airport a minimum of 75 minutes before the flight (having access to J/F checkin and hence minimal queues there) and have never been very tight on time.