News update: PSLV-C44 launch successful + some known and unknown things

Launch Image

the ready rocket

Launch and onboard camera view of satellite separation

(Source: TOI
& nasaspaceflight forum)

ISRO's first mission of new year, PSLV-C44 launched its payload on Thursday- 11.37 pm from 1st Launch Pad at SDSC/SHAR. This was first flight of PSLV-DL version and 46th in total for PSLV rocket. This was the lowest orbit insertion by ISRO to date. After Microsat-R separation, PS-4 re-ignited and shut off twice before reaching designed circular orbit of altitude= 450 km. ISRO officials say that PS-4 will stay "alive" for 6 months (?).

1. Microsat-R: DRDO imaging/reconnaissance satellite for military purposes, satellite separated at an altitude of 277 km, 740 kg weight,
2. Kalamsat: 10cm cubesat made by students, 1.2 kg weight, has solar panels (?).

My doubts:

1. when does PS-4 stage become useless? TOI report says 'in 6 months'...but how? battery power or solar energy (as suggested by TOI report, does a rocket stage really have solar panels?)?
2. some reports say that Kalamsat is powered by PS-4 batteries but the cubesat is said to have life of only 15 hours, so which one is true... 6 months or 15 hours?
3. does a 1.2 kg cubesat really have "solar panels" as TOI reports? if that is true...why will it remain operational for only 15 hours?
4. how can TOI report claim that, this is a "technology that can eventually reduce space debris"?

I think this is purely a case wrong reporting by TOI science editor.