How many modules are too many for a community site?

Hi

I am making a community site, whose functionality I'm generally satisfied with.
I am using a good number of modules, that are listed below to enable it to do the different things I have planned for it.
I have however heard about the issue of some modules using high memory resources and so I need to know whether I already have too many or not, and if so, which ones are likely to be the "gas guzzlers" and see what to do about them.
I find it hard to get rid of any of them, unless I really must.
I dont expect to have too many users for a while to come and intend to start with shared hosting, probably at Hostmonster, Site5, Dot5hosting or other host in that general class. The site is currently still under development at a free host.

Here are the modules:

ALL Core optional except book, legacy, locale, & ping
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ACL, Forum Access, Front Page,
Audio(audio, getID3),

Currency,Currency API,Event,
Image, image gallery, Javascript tools (collapsiblock, javascript tools, tabs)
Ad (embed, external ad, etc), Advanced contact, archive,
auto time zone, bookmark us, contact link, classified ads, F.A.Q,
forward, greybox, xml Sitemap, Guestbook, Ip to country,
login tobbogan, node images, page array, pathauto, persistent
login, poormanscron, postcard, printable, pdfview, recipe, service links,
signup, site map, spam, token, update status, upload preview, url icon,
extended user notifications, user protect, webform, weight
Smileys, captcha (captcha, capture image)
Syndication
jQuery Update,
External links
Video (Video, video upload)
Views (Views, Bonus audio playlist, Bonus summary + full view, Views RSS, Views UI)
Voting API
JRating
Disabled but desirable – Invite, Mass contact, Notify, Organic groups, OG Forums, panels

Would it make a big difference in case resources are an issue, to add OG, OG Groups, ... ?
Is there any way to trim them & have similar functionality, e.g. by using better alternatives.

So any reassurance, any advice?

Thanks