Validacion W3C, vale la pena arreglar esto?

[willycarp]

Hola gente!
Acabo de armar una pagina muy basica para un fumigador a la cual le realicé la validacion W3C... ya solucioné unos errores que me marcaba pero no entiendo que me quieren decir con lo siguiente:

Line 110, Column 106: there is no attribute "rel"
… title="" alt="casa desinfectada" rel="<h3>Foto numero 1</h3> Texto de ejemplo…
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You have used the attribute named above in your document, but the document type you are using does not support that attribute for this element. This error is often caused by incorrect use of the "Strict" document type with a document that uses frames (e.g. you must use the "Transitional" document type to get the "target" attribute), or by using vendor proprietary extensions such as "marginheight" (this is usually fixed by using CSS to achieve the desired effect instead).

This error may also result if the element itself is not supported in the document type you are using, as an undefined element will have no supported attributes; in this case, see the element-undefined error message for further information.

How to fix: check the spelling and case of the element and attribute, (Remember XHTML is all lower-case) and/or check that they are both allowed in the chosen document type, and/or use CSS instead of this attribute. If you received this error when using the <embed> element to incorporate flash media in a Web page, see the FAQ item on valid flash.

Line 110, Column 107: character "<" is the first character of a delimiter but occurred as data
…title="" alt="casa desinfectada" rel="<h3>Foto numero 1</h3> Texto de ejemplo.…
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This message may appear in several cases:

You tried to include the "<" character in your page: you should escape it as "&lt;"
You used an unescaped ampersand "&": this may be valid in some contexts, but it is recommended to use "&amp;", which is always safe.
Another possibility is that you forgot to close quotes in a previous tag.

El error forma parte de un slider muy basico que saqué de un blog!


Les dejo la pagina que hice para que puedan ver el codigo: http://www.fumisur.com.ar


Ahora tengo una pregunta... ¿se justifica corregir toooodos los errores para lograr obtener la validación o no? Es decir, si la pagina funciona correctamente y el usuario comun ni sabe lo que es la W3C, igual nos conviene volvernos loco para dejar la web limpia de errores??

Graciassss!!