The excerpt has a maximum lenght of 55 words, so even if you try to cut your text at say 70 words, the_excerpt() will ignore that and only show 55 words.
To remove[...] from the read more tag, simply find the_content() and replace it with the_content('',FALSE,'');. You can also use the_content('Read more...'); to display a text after the read more tag, in this case Read more....
If you need to remove [...] from the excerpt, you can do this in your functions.php
function new_excerpt_more($more) {
global $post;
return '';
}
add_filter('excerpt_more', 'new_excerpt_more');
You can also add a custom text or link inside the '' if you need something else to dispay