an exhausting question (pun intended)

I'm trying to put together my first build and i want to cut off the muffler and instead drill a hole in the frame and run the exhaust into the frame and have it exhaust out at the seatpost and attach a deflector in that area so the smoke goes down towards the tire. I'm homeless and don't have any tools. My question is can i just run the exhaust thru that way or does it need to be baffled? i'm trying to keep the noise down as this is all in the effort of hiding the fact that i have a gas motor on the bike. i plan on packing the gas tank inside of the frame area and sticky backed velcroing two painted peices of cut cookie sheets over the engine area. I saw a place where they do welding on my way to work i plan on asking them about doing it possibly but was also thinking i could do it possibly with just a drill and bit with some liquid steel or jb weld and a small peice of copper pipe of the right width. I wanted to check with more experienced people to see what there thoughts were on the possibilitys. i've got a kmart bike, a schwinn riverside beach cruiser. I also planned on detaching and attaching a bar of metal to widen the two bars that run from the back sprocket of the frame to the front fork to velcro strap in the gas tank and still have the top fit between the bars and be able to screw off the gas cap. i'm trying to run the exhaust thru the frame cause that muffler hanging off the side is a dead giveaway. i thought to make a cutout in the frame and install the baffling but i'm sure that that would compromise the frame too much. I was also thinking to apply this guys intake extension Intake Extension for More Low RPM Power more because i had to than i wanted to because packing all those items inside of the bars it seems i need the intake out of the way a scooch. it looks like i have to cut the intake manifold. i'm scared guys. i'm an ex carpenter turned dishwasher not a mechanic turned welder.