To do more than thousands directory submission for one keyword and also for all pages of website it is good or bad...?
I've heard if Google sees your links jump way up, it counts it as spam. It has to be done over time naturally.
make a unique content... like change description and title about your site and submit 2-3 directory per day... and it will help you to get index...
Bad very bad. Be ready to get your website banned from search engines. Any spikes or instant grows are bad for health!
Its a bad idea for only one keyword, and worth remembering that searchers often use 2 or more keywords.
always use multiple keywords that target to one concept lke for a classified ads you can have keywords and similar..
I think it is bad as it is very easy for Google to find out the footprint if you are building links in this way.
You need to be changing the title, description and keywords, when doing directory submissions. But then again, most directories don't allow keywords in the description section.