New tenant issues-What the landlord/syndic can do?

(Please forgive me in writing this in English; My french is at very beginner level)

I am a new landlord plus syndic of a "maison de maitre" converted to three apartments.
I own ~80% of the building.

I live in the ground floor. Unknowingly, I leased my first floor apartment for 9 years last July 2011 to two students.
I assumed they were couple or married. These couple?? occupied this apartment since September 2011.

After 3 or months, problems started from them. Although they pay rent in time,
they are treating this "single family/maison de maitre" as their own.

# They do not respect other tenants or adjacent neighbors in the street
# They converted garage into a gymnastic centre with bunch of gym equipments setup.They use electrical heating and music doing gym in the garage. (we need to pass through their garage to goto our garage or backgarden)
# They also have table football and table tennis setup in one of the bedrooms.
# They play indoor football or ping pong even after 10PM with their visitor friends. WE told them children cannot sleep but they do not stop playing indoor games after 10 PM.
# They do conduct party every weekend with friends. Sometimes They make loud noise after 10 PM.(Building from 70s and not sound-proof)
# They moved out barbeque to the common backgarden and left it there for more than a week now.
# I had to call them at atleast twice to remove their car from the common area as my car couldn't enter or leave
# I am worried when they will bring out thier garden tabel/chair and leave it in common area.
# They also invite friends who come to play table tennis pr football with them either in the common backgarden or in their garage or in one of their bedrooms.
# They flush out at least bathtubs every day since they know they have to pay for water based on quotite part.

## (Q1) Do I have the right to evict them (without paying any penalty from my side) if this becomes unbearable?
(I have a valid reason as my 3 children need more space so we can always sent a six months notice requesting them to quit as we need it for our children, )
The template I used for signing the contract was The contract templates were taken from PIM and the form is “contrat de bail de résidence principale pour un immeuble sis dans la Région de Bruxelles-Capitale” <https://www.pim.be/telechargement/bail_principal_v2009_bruxelles.pdf> :
My contract say:
"- à tout moment, en donnant un congé six mois à l’avance, s’il a l’intention d’occuper le bien personnellement et effectivement ou de le faire occuper de la même manière par ses descendants, ses enfants adoptifs, ses ascendants, son conjoint, les descendants,"

##(Q2) As a syndic of this apartment, can I send out following "REGLEMENT D'ORDRE INTERIEUR "?
    (a) Tenants & inmates need to respect other tenants/neighbors
    (b) Tenants & inmates need to respect the apartment
    (c) Keep the front door to street locked after 8 PM
    (d) Keep the garage door and access to garage door locked all the time
    (e) Except for loading/unloading, cars should not be parked in access-road/approach to our garage or in front of the garage
    (f) Do not play any indoor games after 8 PM
    (g) Do not make loud noise/music/sound after 8 PM
    (h) Do not use high heels shoes in the upper floors
    (i) Using fire crackers are not allowed anywhere in the building premises
    (j) Setting up barbeque are not allowed anywhere in the building premises
    (h) Electrical heater should not be used anywhere in the building premises.
    (i) No visitor or guest should be allowed access to garage, back garden or garage access area
    (j) No visitors or guests should be allowed to play any indoor or outdoor sports or games in the building premises
    (k) Apartment premises, inside or outside, should not be used as a party venue or weekend meeting center???
    (l) If inmates cannot help with cutting/pruning garden fence, we would hire external party to cut fence and add it common garden expenses.
    (m) No personal items should be left in the common access areas, in front of garage, Access to garage, at the road giving access to garage. This includes barbeque, garden chair, table foot ball, tennis table etc..
·     (n) Garage could be used for organized storage of acceptable material or as a garage. Garage should not be used as a gymnastics or sports center

##(Q3) As my 8 year old children play with neighbor's children in their garden or the neighbors children play with our children in our garden, will point (i) and (j) apply to our children too???
##(Q4) We do have a small shoe rack and buggy in the common area but without hindering anybody's passage. Should we remove if point (m) need to gets applied?