below rm600, can get Huawei Honor 3X G750 with its 13MP-5MP camera or Lenovo A936 / Golden Warrior Note 8 also with 13MP-5MP camera; both octa-cores. can also look for Lenovo Sisley S90, perhaps better for selfie with its 13MP-8MP camera but have quad-core and no microsd slot.
most android phones do not require you to root nowadays. only if you want to install certain apps, but for normal usage, no need rooting.

your requirements are too broad, if you like big screen, can go for Samsung Galaxy Note 3 with its 5.7-inch screen. if you want great camera, can go for Meizu MX4 Pro with its 20.7MP-5MP camera, great selfie camera can go for Lenovo Vibe Shot Z90 with its 16MP-8MP camera. personally for me, i would go with Huawei Honor 6 Plus, best bang for buck at the moment.
with that budget, can go for Asus Zenfone 6 (A600CG) with its Li-Po 3300 mAh battery.

or you can always suggest your dad to carry with him a powerbank?
if can stretch a bit to RM549, best bang for buck would be Lenovo A936 / Golden Warrior Note 8. 6-inch screen, octa-core processor, 2GB RAM and 13MP-5MP camera. if have to be below RM500, then Xiaomi Redmi Note 4G with its 5.5-inch screen, quad-core processor, 1GB RAM and 13MP-5MP camera.

Upgrade?
Lenovo A7000 Plus
Meizu M2 Note
Xiaomi Redmi Note 2

I would stay away from Alcatel. - my opinion

Upgrade?
Lenovo A7000 Plus
Meizu M2 Note
Xiaomi Redmi Note 2

I would stay away from Alcatel. - my opinion

Well.. technology move too fast.. if yours ain't broken or unusable, then why change? unless you have extra cash to spend on gadgets.

Humble opinion ahead, if you don't face any quality issue, then the Meizu M1 Note is pretty good at the price selling.
It is faster than Meizu M2 Note, and of better quality than Lenovo A7000 Plus, which has similar spec.

The only worthy upgrade would be Xiaomi Redmi Note 2, which use a higher end processor, and upgraded the graphic chip too, Mediatek Helio X10, but it is still not officially available at Malaysia. Won't recommend you buy AP set.

On usage wise, it is depend on what you really need.
Overall, Meizu M1 Note has a good camera, good battery life, and good screen.
For some easy comparison, it's performance is better than a Samsung Galaxy Note 2, but loose to Samsung Galaxy Note 3.

The only downside is it don't has expandable memory, and the processor's graphic chip is not high end enough for today standard, you may notice the lag on playing high 3D graphic game, but still playable.
You can turn down the graphic setting to make the game running smoother.
Meaning, if you can live with it's only 16GB or 32GB memory, and not playing any high 3D game like Asphalt 8, Real Racing 3, Modern Combat 5, then no point for you to consider an upgrade.

It is a never ending comparison, where in future for sure there will be higher end phone with similar cheap price available on the market.

worse than m1 bro