"열으셧습니다" => 여셨습니다 (correct form). (열다 (open) -> 여시다 (honorific form) -> 여셨습니다 (formal, polite sentence ending)) 열으셨습니다 is a bad, ungrammatical form. This type of mistakes are often made, perhaps by analogy with other verbs conjugating with -으- in it. (먹다 -> 먹으면, 갚다 -> 갚으시다, 잦다 -> 잦으시다). But most verbs with ㄹ 받침 syllable conjugates without adding 으 (ex: 물다->무시다, 밀다->밀면, 갈다->가니까). 여섰습니다 is a polite ending form of 여시다, an honorific version of 열다(open). So it means "You opened (it)" in honorific form (여시다), as a TV show MC might say to the participants. 달려들다 is a formation of 달리다 (run) + 아/어 + 들다 (come in, turn in). It means run/dash to/onto/into someone/something. In some cases it can mean "attack" but not necessarily. 달려들어요 여러분 is more like "Run to it, everybody", or "Make your move (to something), everyone".