Ruling on not doing some mustahabb deeds in order to open the hearts of the people of bid’ah whom one is calling to Islam

Firstly, if you are doing an action which is proven to
be part of the Sunnah of the Prophet
(peace and blessings of Allaah be upon him), it is
not right to say that you want to make some changes to it, because it is right and proper
in and of itself. But the reason behind your question seems to be that you want to keep
from doing it openly in front of some people for a specific purpose, or to avoid a
specific evil.

Secondly, talking about Tawheed and basic matters of aqeedah and
teaching people about these things among the people you describe, is undoubtedly more
important. Tawheed is the key to the call of the Messengers (peace be upon them) and the
first duty of the one who is accountable. It is the condition for all other deeds to be
accepted. If it is clear to you, or you believe it to be most likely that adhering to some
mustahabb actions, such as moving your finger etc., may cause confusion or fitnah, or
cause you trouble, or damage your reputation so that people are put off you and do not
listen to you, or distract the people you are addressing from what is more important, then
there is nothing wrong with not doing it for this reason in these circumstances. Allaah
knows best what your intention is, and that you are not giving it up out of negligence,
but in the interests of spreading Islam, so you will be rewarded for this, in sha Allah.
May Allaah bless our Prophet Muhammad.