Does Malaysia Airlines allow bringing food in the checked-in baggage?
Strictly speaking, it appears not. See last page of Malaysia Airlines Baggage Information:
Malaysia Airlines advises you that following items may not be included in your baggage and liability is limited under the applicable international Convention for your damage or loss.
Cash, negotiable bonds, deed, etc; Jewellery, antiques or similar valuable items; Any item of a fragile or brittle nature (e.g. glassware); Electrical or electronic components (e.g. computer, camera, mobile phone, audio equipment); Food or any perishable item; Any item that has insufficient packaging (e.g. surfboard, bicycle, musical instrument)
However meat pies are not classified by them as dangerous goods (ibid) so I doubt the airline would mind - just does not accept responsibility for them.
Will my food spoil or anything due to temperature, pressure, or whatever possible reason during flight?
There is advice about that here: Would uncooked bacon go bad in a transatlantic flight?.
If the pies are destined to be cooked I'd take the risk, but not otherwise.