No, the BT omega does not have any rails to mount any sights on. A custom rail would need to be fitted and drilled into the handle to support any sights.
AIM B Style Red Dot Gun Sight-wrong your barrel
On the top of the Recon CS-6 there is a tactical rail (look it up if you are not familiar with it) where the sight can be attached.
Truthfully, You don't really need an optical zoom site. A red dot is the most you need for paintball. Paintball markers arn't accurate enough to utilize a optical zoom site correctly.
In general scopes are not very useful in Paintball due to the relative inaccuracy of the Paintball itself and the tunnel vision effect of the scope. but if your Paintball gun had weaver or 3/8 rails, you can mount whatever scope (or sight, a better option) you wanted on it
No. You need an offset rail or the sight will be blocked by the hopper.
generally the iron sights at the front and back of the marker, if you line them up you will have an idea of where the paintball will go, but paintballs are very inaccurate so scopes or lasers or anything like them is pretty useless
Since the MR2 has 3/8 rails, and the dlb140r has 7/8 rail mounts you need a rail changer. In the related links is one for around $20 US.
Add a compensator, weaver accessory rail, Red dot sight and tactical flashlight.
press down on the front sight and turn the hopper downwards
No. It does not have any rails, nor is it accurate enough to need one.
Yes, any scope with 8/11 rail attachments.
There are no "good" scopes for that price. If you haven't the money to buy a decent scope, odds are you don't need one.