Okay, in many Places, especially Topics dealing with Dragonball AF, people go crazy and make up insane Fantasy fusions that are just downright stupid.
Okay, in all Fairness, some of them might work. For example: Vegeta and Trunks have similair height and in the Cell saga had very close Power levels. In this respect the Fusion Dance might work well for them. HOWEVER there is a Chance that if it works anything like inbreeding (brother and sister have a kid) then there would be SERIOUS problems. Looking at it in a Genetic level it would be a disaster. Same goes for Goku/Gohan.
However Potara Fusion might not do this because it is a better uniter. Of course, its power is based on the DIVERSITY of the two people outside of height and strength, so a Father Son Combination would likely result in just adding the 2 PL's together. Compared to Vegito this is nothing.
But lets look at other Fusions, such as Gohan plus Piccolo. This would'nt work in either fusion because of Species, power difference, and many other factors. Even in Potara it wouldn't do much to help.
Now, people talk about Fusing Fusion with Fusion, and that just pisses me off. Why would two fused fighters fuse? Its stupid and pointless and the Personality clash might case a Paradox which would destroy the fabric of time.
Some suggest 2 people do the dance, then 2 others do it as well and then they use the Potara's. This wouldn't work because it still wouldn't negate the effect of the Time Limit and they would...suffer being ripped apart from many sides, it would not be cool. My reasoning behind this is Fusions suffer the same effects as normal people do from Transforming, so it should be the same.
Also, people could just cross Potara many times with others. This would work physically but in the end the Character would just be a lot like Cell but the name would be stupid sounding like Gokentrutendiccolohantenkugetanail.
And in all fairness, if you can say that 5 times fast, you should be the president. (Both Candidates would fail the test)