Well,
Water level is decreasing?
These so called bubles can be seen in almost all cars radiator, The thing is they give acclerator and say see sir bubbles ban raha hai I mean aur kia bana jub water pump pushes water into the pipes
Leave the car as it is if your water level is not decreasing too much or you see sign of oil and water mixing when you pull out the dipstick.
Now let me tell you a story that happend to me today.
I also get my readiator fixed for small leak and i keep my car's thermostate in working order along with auto Fan so it always stays at middle or water temp at 80c.
Now as soon as he opened one pipe he was like OH SIR APP KE GARI TU OVER HEAT HAI APP KO PRESSURE NAZAR ARAHA HAI, i told him mama stop the leak mujha yeh chawala mut maro i got thermostate valve and it will make the engine heat to optimum temp. Phir dobara nahi bola
BTW if you still want to change gaskit, Phir make sure they open you car's engine when car's engine is cold. Like park at his workshop for atleast 3 to 4 hours.
Check the rings as well ab head khul he raha hai tu rings bhi dal deina itna ziada expensive nahi honga, Also get the valve check.
Most of the times what happends is when you change gaskit and bcoz the valves or rings were weak and with new gaskit as the pressure increases one of these things fails and you end up with a engine that is burning oil.