Re: sometimes I get posts deleted.. do admins have a quota to fulfil?
Thanks man, im so pleased im not the only one! and thanks for the merit and looking out for me. Its disheartening when you engage with a topic and have it deleted 
Suchmoon had a possible reason:
Those posts in the screenshot seem like generic talking points and one was in a 200-page thread, another in a 10+ page thread, both seem to be just addressing the thread title and not engaging in the discussion. Could be considered low value posts depending on where exactly in the thread they were etc. Edit: the battery concern was definitely expressed in that thread about a dozen times so if FM posted towards the end of the thread then it indicates they didn't read it or didn't care.
A lot of those big megathreads are often used by people in signature campaigns to meet their posting quota so moderators in a response to try to stop the practice delete posts that are deemed "low quality" (Rule 1)
The spammers and bots are making it hard for people on the forum - especially those starting out.
Don't let it affect you. I've also had posts deleted where I have been puzzled. It is sometimes hard for the moderators to judge those that have an intent to engage in conversation and those that just churn out content to meet their signature campaign requirements.