In Islam, duʿāʾ (Arabic: دُعَاء, plural: ʾadʿiyah أدْعِيَة), literally meaning "invocation", is an act of supplication. The term is derived from an Arabic word meaning to 'call out' or to 'summon', and Muslims regard this as a profound act of worship.
If a person promises Allah (SWT) to do or not to do something, he must fulfill his promise with out fail. If he breaks his promise, he has then committed a sinful act and must expiate by either fasting two months or feeding sixty poor believers. This is called Kaffara of 'Ahd كفارة العهد.
Understanding the meaning of Du'a is better than reading with out understanding.
Sawab depends on the intention and degree of the sincerity and dedication, not merely on the language.
In the technical sense of the use of the word "authentic (sahih)", with respect to having a solid, complete chain of narration and solid textual sourcing, Du'a Sanamay Quraysh is not authentic.
(I say "technical sense" to specify what is meant because there are a lot of ways that people casually use the word "authentic" today.)
As for whether Imam 'Ali (A) actually said it... God knows best.
In any case, you have the option to recite it if it calls to you and you find benefit in it, and you have the option to leave it aside if you prefer to.
Thank you for your question. Reciting whilst not knowing the rules of tajwid is not a sin, but a person should endeavour to pronounce the Arabic properly.
May you always be successful
Yes, it is authentic and narrated in many authentic books. Allama Majlisi narrated it in Biharul Anwaar, volume 99, page 247. Dua Tawassul was narrated by Mohammad Bin Babawayh from Infallible Imams.
There are always persons who create doubts because of their own misunderstandings or way of thinking, but their doubts are for them only, because our leading scholars who have much more knowledge like Allama Majlisi and leading Maraaji' are the scholars to be followed.
It is recommended to praise and glorify Allah and recite Salawaat before Du'a, then recite Du'a or supplicate to Allah (SWT) seeking your need, then recite Salawaat after Du'a.
It is highly recommended to pray for your parents , relatives and Mo'mineen before or with praying for yourself.
It is permissible to recite Du'a Tawassul during Sajdah because the Sajdah is only for Allah (SWT) and never for any one else but Allah. During Sajda Sahw, we recite (Bismillah a Billah, Assalamu Alayka Ayyuha Annabiyyu Wa Rahmatullah Wa Barakatuh). It does not mean that we doing Sajda for the Prophet (SAWA) but for Allah (SWT) only. Addressing the Prophet or any Ma'soom during Sajdah does not make the Sajdah for him at all but it remains always for Allah (SWT). It menas hat you are talking to them while prostrating to Allah (SWT).
It is good to listen to the recorded recitation of Quran or Dua. If the recitation is live by a present reciter, it will be important to listen, but it does not mean disrespect if you are doing something else while the recording is played. Disrespect depends on the intention and the impact on people. No believer will ever have an intention to disrespect Quranic or Du'a recitation.
Repeating Estighfaar is very helpful as well as repeating LA HAWLA WALA QOWWATA ELLA BILLAH.
When the believer remembers the fact of the grave which is our place for long period, and remembers the Paradise for the pious and Hellfire for wrongdoers, it should make him away from sinful acts.
It is good to recite these Quranic supplications (RABBI A'OOTHO BIKA MIN HAMAZAAT ESH SHAYATEEN WA A'OOTHO BIKA RABBI AN YAHDHOROON).
Also this supplication (ALLAHUMMA AKHRIJ HUBBAD DUNYA MIN QALBI)
It is also useful to remember the end of those who committed sexual sins and got nothing but disaster in this life and hereafter. That should be enough lesson for every sensible person.
Du'a Mujeer is one of the authentic supplications narrated from the Prophet Muhammad (SAWA) from Jabraeel (AS) when the Prophet was praying in Maqam Ebrahim which is in front of the Ka'bah.
Du'a al-Mujeer is narrated by our prominent scholars like al-Kaf'ami inAl-Balad Al-Ameen and Al-Misbah.
Yes it is valid. Reciting Du'a of fasting is not obligatory but just recommended.