haha, i know that about pakthuns :D. and i appreciated the concept when my mother told me about their this tradition.
khair mubarik in advance. and i also take my eidi in advance. thank you 
and for your furniture it depends on the colour of the rooms. the safest colour to work with is beige and you can mix and match it with black leather decors, adding hint of green (plants).
if the room colours are white then you can give a modern touch to it, and get more edgy furniture. this i personally think that suits you more in your current life style. and instead of going with the paintings, get your geometric photography enlarged (if you are into photography). IKEA furniture is not sleek, but its very edgy.
but if the rooms are painted in some wild colour then u have to come up with the themes.
i am suggesting you to decorate your house keeping colour of the room in mind because it is not all about furniture. it is about inviting someone into the space. so my suggestions will not to invest in something that you will throw eventually. so pick the colour scheme (for e.g your favourite colour and its complimentary colours) and shop acc to that. otherwise your mother will again fail you but this time for the imbalancing the space.