'Taqiyya' - Jihad vs Suicide as wrong

Allowed in Sunni Islam?

"Some Sunnis assert that al-Taqiyya is an act of pure hypocrisy that serves to conceal the truth and reveal that which is the exact opposite (of the
truth). Furthermore, according to those Sunnis, al-Taqiyya constitutes a lack of faith and trust in Allah (SWT) because the person who conceals his
beliefs to spare himself from eminent danger is fearful of humans, when, in fact, he should be fearful of Allah (SWT) only. As such, this person is a
coward."

The same site says that Rejecting Taqiyya is rejecting the Qur'an, and gives these sources:

Ibn Abbas
said: "al-Taqiyya is with the tongue only; he who has been COERCED into saying that which angers Allah (SWT), and his heart is comfortable (i.e., his TRUE faith has NOT been shaken.), then (saying that which he has been coerced to say) will NOT harm him (at all); (because) al-
Taqiyya is with the tongue only, (NOT the heart)."

Abu Bakr al-Razi in his book, "Ahkam al-Quran," v2, p10, has explained the aforementioned verse "...except by way of precaution ("tat-taqooh"),that ye may guard yourselves ("tooqatan") from them....[3:28]" by affirming that al-Taqiyya should be used when one is afraid for life and/or limb. In addition, he has narrated that Qutadah said with regards to the above
verse: "It is permissible to speak words of unbelief when al-Taqiyya is mandatory."

There are other sources too.
Where does Jihad come into this though?

You are allowed to protect your life by denying Islam etc if that is required.

But the general idea of taqiyah that may have developed by the shia could potentially be much more though, turning it into... plain deceit.

"For too long, we have been a passively tolerant society, saying to our citizens 'as long as you obey the law, we will leave you alone'" - David Cameron, UK Prime Minister. 13 May 2015.

You wrote:
You are allowed to protect your life by denying Islam etc if that is required.

But the general idea of taqiyah that may have developed by the shia could potentially be much more though, turning it into... plain deceit.

Why has it been developed more by Shi'as?

#Before you look at the thorns of the rose , look at it's beauty. Before you complain about the heat of the sun , enjoy it's light. Before you complain about the blackness of the night, think of it's peace and quiet... #

They were a minority and always have been (currently between about 7 and 14% of the Muslim population). They may have felt threatened and some of the branches of shiaism were/are really "out there", so they may have felt threatened because of their beliefs.

"For too long, we have been a passively tolerant society, saying to our citizens 'as long as you obey the law, we will leave you alone'" - David Cameron, UK Prime Minister. 13 May 2015.

Another problem with the Shia view of taqiyyah as opposed to simple being allowed to save your life in times of extreme danger etc is that... well...

Both shias and Sunnis accept that the Imams were great people. However, when Imam Ali (ra) said things in convenient to them, or the others did (like we know that the 6th Imam did not challenge the authority of the caliph at the time and stayed away from the politics of it all etc.), they consider those events to be "taqiyyah".

this leads to a situation for them where you cannot trust your sources as you cannot know if the person was "doing taqiyyah" or saying what they felt was correct.

"For too long, we have been a passively tolerant society, saying to our citizens 'as long as you obey the law, we will leave you alone'" - David Cameron, UK Prime Minister. 13 May 2015.