These are all good words. You can always use them if they have a meaning you want to express. "Acknowledge" is not a word that one would normally use to express gratitude. "Adventurous" is usually positive because an "adventure" is usually a good thing. However, it can also be the opposite because adventures do not always turn out well. "Affective" is almost a medical word. It's not used much in ordinary conversation. When it is used, it will usually be in a negative way. It would mean something like emotional, but in a phony or abnormal manner. "Alter" is similar to "change" except that it expresses more intent. "Alter" means "cause to change".

All of them are formal.

Hi Lucy, "Acknowledge" is used to show you accept something exists or is true. (it can sound a bit formal) Ex: I acknowledge that he wants to talk to me, but I don't want to talk to him. (I know he wants to talk, but I don't want to). We can use 'adopt' when we start to do a new habit or start a new lifestyle. ('adopting advice' sounds slightly more formal than 'taking advice'). I want to be healthy, so I'm 'adopting' the advice you gave me about running and eating more vegetables. Adventurous sounds more positive to me. A negative word might be "reckless". Affective is usually used in medical situations (for example, when talking about an affective disorder). Emotional is used more casually (They often get emotional). "Alter" is used when you make something a little different, while "change" can be used for small differences or making something completely different (it's more broad). I hope that helps!