1 A new Muslimah does not wear her hijab in the countryside. Can the Jinn see her and should she cover her head when she is outdoors, even if there are no humans around?
2 Another sister does not pray at work because there is no private place to pray. So she prays all her prayers late (after work). Is it permissible for her to pray sitting at her desk or does that only apply to people who are physically unable to stand for prayer?
3 For questions such as these do you need a Fatwa or can you use common sense? On one hand I am told that Islam is very easy and on the other that you need a Fatwa for everything that is not covered by Qur'an or Ahadith. Which is true please?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

No doubt, Hijaab is compulsory on all Muslim women in order to protect them from the sight of non-Mahram men. But if the woman is alone in her home or in a place where no non-Mahram man can see her, she is not obliged to put on her Hijab and can, consequently, uncover her face, head, arms and forearms. On the other hand, no person (man or woman) should uncover his/her Awrah (private parts) even when alone and where no one can see him/her.

The Prophet was once asked the following question: "What can we uncover about our ‘Awrah and what should we keep covered?" He said: "Guard your Awrah except from your wife or your woman slave". The questioner asked: "What if the man is alone with another man?" The Prophet replied: "If you can keep it from being seen by any person do that". The questioner said: "What if a man is alone". He replied: "Allah deserves our shyness more than anyone else". [At-Tirmithi and Ibn Majah].

It is forbidden to delay the prayer from its prescribed fixed time for work or for any other reason. Allah Says (what means): {the prayer is enjoined on the believers at fixed hours.} [Quran 4: 103]. Allah has threatened anyone who neglects praying or delays the prayer from its fixed time. Allah Says (what means): {Then, there has succeeded them a posterity who have given up As-Salaat (the prayers) [i.e. made their Salaat (prayers) to be lost, either by not offering them or by not offering them perfectly or by not offering them in their proper fixed times, etc.] and have followed lusts. So they will be thrown in Hell.} [Quran 19: 59].

So, this sister should look for a place in her work place where she could perform her prayers at in their fixed times. As for praying seated, this suffices only in Nafl (supererogatory prayers) even if the reward of praying normally (standing up) is twice the reward of praying seated.

So, Fard (obligatory prayers) should not be performed in the sitting position unless one is physically unable to pray standing.

Islam is the religion of easiness and simplicity. Allah Says (what means): {Allah intends for you ease, and He does not want to make things difficult for you.} [Quran 2: 185]. The Prophet also said: “Religion is very easy” [Al-Bukhari]. Allah Ordered the people to ask the scholars and return to them whenever they need to know a particular ruling. Allah Says (what means): {So ask of those who know the Scripture [learned men of the Taurat (Torah) and the Injeel (Gospel)], if you know not.} [Quran 16: 43].

It is forbidden for the Muslim to perform any kind of worship or do any kind of transaction or other matters without being aware of the Sharee’ah ruling about that matter (whether it is allowed or forbidden).

In order to know such rulings one should consult the books of the scholars if he can understand them, or ask scholars directly and act according to their Fatwa.

A person might, for instance, stick to a form of worship which causes much hardship to him and when he asks the scholars, he discovers the real and accurate way which is always easy and simple. Easiness does not necessarily mean lack of hardship and it does not always match what the person wishes. Orders and commands imply all the time some sort of hardship to put the person to the test of try him to see how well he will stick to his religion.

Allah knows best.