Wall form construction is a different structural design. The photo shows low quality construction - brick mortar seems inadequate, steel link seems too few, concrete should be done for whole beam at one go.

No. It is not a good practice.

I think the other guy was referring to precast wall form construction ie: load bearing wall. It's a completely different design.

The top beam is meant to hold the deadload of the roof. Note that the brickwall is not meant to be a load bearing wall. However, agree that the roof may not collapse and most renovation contractors do not know and don't practise good construction practices.

Yes, steel bars come in 12m length. On the lapping of steel bars, it ranges from 35D to 50D, depending on the locations etc.

It should be noted that good practice is not the same as normal practice. If we use brick as support, can we ensure that the water in the concrete is not lost through the gaps in the brick or absorbed by the bricks? If this happened, the concrete strength of the beam will be affected. Concrete needs water to gain strength.

Another point to note is that all beams and columns should be cast at one single stage. If it is not, then we will need to roughten the surface to ensure better bonding. In some cases, bonding agent is required but not usually used in renovation. Even in two stage casting, we should not leave the joint at the maximum bending moment location which the guy in the photo is doing.

On the links in the beam, the code of practice states that it must not be more than half the depth of the beam. In the above photos, it is nearly 2X depth of beam.

So, if this is the normal practice, it only prove that normal practice does not comply to good practice.