Is there a blood clot that is not so dangerous and may easier to dissolve ?
All blood clots are potentially dangerous. My Grandad had a bunch of blood clots that no-one knew about until he had a series of really bad strokes that nearly killed him (caused by the clots). He now lives in a Nursing home because he is paralyzed for the most part down his right side and unable to look after himself. He's also in blood thinners to try and stop any new clots from forming.
I've never heard of dissolving a blood clot (you'd run the risk of dissolving normal blood, wouldn't you?) - often removing then either relies on them being dislodged and hopefully broken up in the blood stream, or surgery to physically remove them. There are all different kinds of blood clots too - some form slowly, some form quick, others are small, others are big. Some are more dangerous than others, but all are potentially dangerous.
I was in the hospital for a week last month with a blood clot in my lungs. Mine was caused by a genetic mutation. I'm on an oral blood thinner (probably for the rest of my life) and taking another one via daily injections in the belly. Blood clots are no joke, especially in vital parts of the body like the heart and lungs, they CAN kill. The lucky thing my doctor told me was that if it didn't kill me in the first hour of having the unbearable pain I was in, it wasn't going to. A chest x-ray didn't pick up the clot, a CAT scan did.
But to answer your question, yes, no matter where the clot is, it has the potential to be dangerous.
I guess the way to look at this is, your blood flows through arteries and veins (which are like pipes) and the blood provides oxygen to various organs. A blood clot prevents the blood from flowing effectively, and that is never a good thing. Not all blood clots will cause stroke or heart attacks, but they are potentially dangerous because if they dislodge and then block up an important vein or artery it could lead to death...
There are ways for doctors to dissolve the clots and apparently exercise can also help dissolve certain clots... http://www.webmd.com/stroke/news/20030508/exercise-can-help-dissolve-blood-clots