Interesting piskei halacha

Here are a few interesting piskei halacha I just saw...

Usual disclaimers apply: I am writing these mostly from memory and any mistakes and inaccuracies should be assumed to be mine, translations and paraphrasing lend to inaccuracies, never follow piskei halacha quoted on the internet or on posters - only follow piskei halacha heard directly from the source or from someone you consider reliable and competent.

1. I saw written in the name of Rav Elyashiv that while it is common to accept chumras and hakpadas during the Aseres Yemei Teshuva, any such hakpados accepted by you are treated like at any other time and are not assumed to be only for the short term. That means that unless you specify a condition upon acceptance that it is only for the 10 days, you would have to do hataras nedarim afterwards to stop the hakpada.

2. Rav Neuwirth, author of Shmiras Shabbos K'Hilchoso, has issued a psak regarding the Rosh Hashan 3 day yom tov. he said that it is common among some avreichim to wear a frock for yom tov, and not for shabbos. In the situation of the 3 day yom tov, it would turn out that he would wear the frock on yom tov and remove it for shabbos, which might be viewed as being disrespectful of the shabbos, as if treating it with less respect. Therefore, he said, in this situation, the frock-wearer should continue wearing the frock throughout the Shabbos as well.

3. Also in the name of Rav Elyashiv I saw written that if one was accustomed to rely on a certain kula, or a psak l'hakeil, and has now decided to follow the more stringent opinion, he need not do teshuva on his previous reliance on the more lenient opinion.

4. A group of avreichim in Bnei Braq have decided to move to another shul, because their shul was too crowded. They found a nearby shul that is Dati Leumi and have been davening there, as over the years its members have moved away so there is plenty of space available.

As the High Holidays approach, they have come into a dilemma. They are nervous that it is inappropriate to be davening there on Rosh Hashana and Yom Kippur, as the shul says the Prayer for the State of Israel.

They went to Rav Shteinman before Rosh Hashana to ask if it is ok, if they should protest, if they should leave the shul, or what to do.

Rav Shteinman's response was that there is absolutely no problem and they can continue to daven there. Rav Shteinman said, "If that is how they daven, it should not disturb you."