Normally getting rid of players is not a way to improve your team. Getting new and better players is how you improve your team.
Church might not be the best safety in the league, but he's the best safety on the team. Until we can get several safeties that are better than him, it makes no sense to get rid of him. I find it strange that Jeff Heath isn't on this list. He was horrible. However, you don't get rid of him or JJ Wilcox, or Morris Claiborne unless you have to in order to create roster spots for new players. All three of them are young and have potential to get better. All three of them are on cheap contracts.
We are basically rid of Spencer already. Since our season is over and he was under a 1-year deal in 2013, he's gone. We would have to decide to sign him to keep him. We also don't have the franchise tag option, because you can only franchise tag a player for two years. We already have. He's more or less a free agent already.
Miles Austin, for cap purposes, is the only one that makes sense on that list. I expect Austin to be a June 1st cut.