A T4i, year in service. Question on lens and service

Hi guys, I am enjoying my T4i for about a year now I must say every party or occasion I go all of my family and friend telling me "Oh yeah , please don't forget that camera of yours" ..Crap sometimes I think they want my camera more than me nah. Anyhow. Right now summer and I live near beach so I am trying to do this,,, don't know how to say but a little documentary about my neighborhood. Beaches, things , people, just things I see every day may be someone will be interested. So after reading a lot of posts and just general things I now understand that I am as a "photographer" (guy with a camera is better term for me) is way more important than equipment and real pros can do amazing things with cheapo cameras (youtube it) so I decided to get very simple video lens and one little accessory that I think I'll need. So once again this is for Video I am trying to shoot.

Lens I've been recommended is Canon F/1.8 II EF for about $60 used.

Now I see 50 mm F/1.4 USM lens for about $350 but is it REALLY that noticeable ? The thing is I am still now to optics and in words I do understand words like crisp, clarity, color, sharpness but at same time let's say this 2 lenses I wish someone took this 2 and just made side by side compare with nice 1080p video in absolutely same conditions and say "you see!, that's why you pay 3.5 times as much" Like I do see 1.4 vs 1.8 but everything else is hard to "read" unless you "see" I am not sure if I am making any sense right now but there are my options. Most people say get cheapest possible and go up as needed, but the way I look at this I don't want to waist that $60 I rather invest in solid lens...but again do I need it, and will I see difference ? Anyhow, just few thoughts from you guys if possible.

And only other thing I found that I need is ND Filter because it's waaaaay to bright for be to shoot the way I want video to look in the end. Wit that I am looking at something like this:

http://www.ebay.com/itm/NATURE-77mm-Fader-ND-W-Camera-lens-Filter-Neutral-Density-ND2-ND400-DSLR-77-mm-/271022159867?pt=Camera_Filters&hash=item3f1a2df7fb

Well tripod is something I already have.

That's it really. Very simple setup to shoot. Now one thing I must mention is this. For several weeks I've been shooting in the house with lens I got with camera STM 18-135 and I am trying to final footage to look maximum possible to "film look" and I must say between color processing and shooting with proper settings it's really doable now. With that lens 1.8 I think I'll be able to do even better. I am working with Premiere Pro to do color correction but it's not easy. Can anyone may be recommend post software that can help me with "film look" and color correcting ? It can be stand alone software or plugin to Premiere Pro.

Please let me know if I am not thinking of something in terms of my documentary.

Next thing is service of my unit. Thanks god camera working like a Swiss clock but I want to ask if I need to do something. With only lens that I have I never took it off for a whole year, I am not sure if that's the way to go or I should not keep lens on the body. Also is there a something I should do with camera or lens to maintain it, store it in specific position may be and in general once I get another lens I'll be switching them, is there something I should know.

That's it really. Thank you guys !