I don't mean the following in the tone it sounds, but y'know, internet.
How are we, a group of unknown internet sorts, supposed to know what you're capable of and if you can ascend class 4 alpine rock? The whole point of a rating system is to convey difficulty as objectively as possible. The route requires several moves of class 4. Up-climb ElD>MW or down-climb MW>ElD. Plain and simple. Holds are abundant and hands are required to move upwards. Exposure and loose rock in spots. Can you do that? I haven't a clue. I wouldn't take certain 5.12 climber friends on this route whereas I'd feel comfortable taking others who don't even know how to tie a figure 8. Ratings might attempt to be objective but climber tolerances certainly are not.
I guess what I'm saying is that we can't accurately and honestly give you reassurances as we don't know you - your skills, capabilities, mental fortitude, tolerances, and so forth. Hundreds (thousands?) of "experienced hikers/backpackers" have traversed successfully sans rope and hundreds have failed to complete it.
On this traverse (4 classics by the way, not 3), I'd be more concerned about the class 2+ crap than the class 4 stuff. There's a bit of junk rock one could run into off-route.
Better (overly-detailed) info to help you assess: http://14ers.com/routemain.php?route=mwil5&peak=Mt.+Wilson%2C+Wilson+Peak%2C+and+El+Diente+Peak