Since you have removed all but one diagrams,
it is difficult to understand what you are saying.

Otherwise what is your assumption is very correct.
There are millions of devices working with open collector
and/or open drains and port0 is not different. If you have
to connect some critical rise time devices then pullup
resistor should be lowest possible as per port0 current sinking
capacity. Most micros are TTL compatible and thus can sink
about 4.8mA which is required for TTL. Therefore 1Kohm is near
resistor. 1.2K better. 4.7K is recommended for rise time upto
300nS which almost all TTL/LSTTL/CMOS devices can tolerate.

It is however not advised to play with LEDs and ports.
To do that you should connect a ULN 2803 (cousin of 2003 but having 8 lines instead of 7). Then connect the LEDs with SERIES
resistors of suitable value to limit current 10mA to each device
to common +ve 5V or other supply. For 5V the resitance should
not be less than 330ohm. Now you can play with port0 without
problem and you can also now increase the pull ups to even 10K.

For diplaying LEDs after connections to TB62726AN you have
to use 1serial output ,latch, enable, clock line and drive
as per device's TRUTH TABLE & TIMING DIAGRAM ON PAGE 3.
As per the diagram posted it is not posible as clock is not
provided.
Wish you all the best in 2007 !!!!