well thats your car haha. check the amp manuals for maxmimum amperage draw and add them together, ensure they are WELL below 150 amps.
as for 3 fuses, you know thats going to give you a headache later if/when a fuse blows right? haha. its good to be safe and all though.
most will have the main fuse at the battery and the fuses in the amps. thats what im running, the fuse i have at the battery has a 3 amp leeway so it can only surge 3amps over the max amp drain of the 2 amps together.
budget/high end wire there is little difference, not when it comes to this size cable and application. speaker wires, video cables, very thin wires then yeah it will make a difference but this is big bulky cable. its all the same under different brands.