The fit must not be right. the Sequoia has a long headtube to give the rider a more upright position. Mine sits parallel to the seat hight. maybe an inch lower.
You can switch to a MB handlebar, but the shifters would need changed, and the brakes separated out.
Comments about the tires are a bit more concerning. You should be on 28's or 32's but they may not fit on the Sequoia which comes with 25's. Maybe the Trek 7.X series would be a better option. The tires are wider, but not mountain bike wide. The 7.5 comes with 32's, and the 7.2 comes with 35's. So by the time you change the tires, rims, brakes, shifters, amd handlebars, you may have bought a bike.